I'm not an auto electrical diagnostic technician but i am an electronic technician turned marine electrician - seeking to enter the automotive electrical field...at home. I simply want to mention that this instruction makes a whoooole lot of sense to me.
Having 5 volt reference issues after doing head gaskets etc,. My $ is on bad wire cuz I can clear codes and runs fantastic. Shut it down,goes into limp mode.
Solid, clear explanations on how to diagnose the problems in a 5-volt reference system. You have spent some of your time in the automotive industry being an instructor. :)
Thanks gene! Actually being an instructor was a long term goal of mine, but I found that youtube allows me to reach such a broader audience that I really enjoy it! Thanks again for all your positive comments on the videos. 👍
Care Bears & My Pony rainbow T-Shirt would have quite an impression as well. Very respectable as we don't see men dressing up these days more of the unkept pubic hair beard dirty hippy tats all over look is common.
Fleet mechanic here. Excellent video. Just about every mechanic I know struggles with 5 volt supply and j1939 problems , including myself. Just applied the first step to a Cummins diesel I was working on today. I found the problem in 5 minutes. Same approach I use for j1939 issues , just never used it for 5 volt supply. Again, excellent video.
Its true.....thats the way to diagnose an electrical fault.......i got more or less same on my 2001 JGC WJ L6.... (i still have to fix the engine injectors wiring harness .... but here on the island its kind of difficult to find a good one to replace it).... but as a matter of fact a good procedure for diagnosting those electrical issues....keep it up ... nice job bro..... and bye the way .. have a merry chrismas......👊🏻👍🏻
Power comes from the pcm, so it should show voltage, but if somewhere downstream the circuitis grounded or shorted to another circuit it will read 0 volts 👍
Thanks for the video! I am dealing with a rainstorm damaged system. Replaced fuseblock, gem, pcm,alternator, starter, and starter relay. Pcm was the last purchase and was not necessary. I replaced the alternator due to high frequency signal disrupting the CPS. After replacing I still have other codes for high voltage/malfunction for a few circuits. Turns out they all share 5v ref. All wires have .0, .1 ohms resistance. All wires show 5.05 volts. Chasing this down has driven me partially insane still love this stuff though.
Finally, someone that took the time to share this in a simple way to understand. Really really, THANK YOU. Now, I can finish up my 99' Suburban with a Crank but won't Start issue since about 3 years... I will update more later. God bless you!
Nice simple electrical explanation. I hate electrical!! I'm the "shotgun" guy. Start replacing sensors and hope it's the right one 😁. I can't tell you how many times I've heard people say it's the PCM. Mechanics as well without even doing any testing. 🤦
Thank you for this video I’ve been trying to diagnose the same issue with my own nine Sierra and I’ve been so lost because I don’t understand the system. This really helped and I will go through all these steps tomorrow.
Thank you so much for uploading this simplified instructional video, absolutely AWESOME, it has helped enormously with a very difficult job we had in our shop,but after watching this video, we nailed it rather rapidly, no better sight than the rear number plate of that eyesore disappearing into the sunset with a happy customer 🙂please post more, it most certainly deserves at least a Billion thumbs up. Bless
@@ReignitedAuto Thank you so much for your kind response, interaction often brings forth mutual respect, we believe your systematic and progressive approach with key points in a simplified way aids better understanding,no long winding excessively technical droning makes for a truly innovative learning experience, your channel is vastly underrated, we shall be seeking out all other videos of yours very soon. my father used to say to me; 'There is always something to learn from everyone regardless of our own personal skill level or knowledge,to show gratitude is the very least we must do,and reflects upon our character and upbringing'. may you go from strength to strength,with greater recognition, as all good intention has never ever gone wasted or fell on deaf ear's, THANK YOU 😇🙂👍
Thank you so much for explaining this so simply. Quick question though. So what voltage readings will you get if a VREF and signal circuit touch, if a VREF and ground circuit touch, and a signal circuit and ground circuit touch for example # 6? Thank you again.
MY code reader os saying PCM isnt equipped. im guessint it is a bad PCM. not the ECM next to the fuse box, but in the driver side wheel well the PCM. a 2003 Caravan. It was confusing for awhile because people anf\d articles are calling the ECM, the PCM.
Can you dissect a wiring diagram for a 2006 Dodge Ram truck 2500 door locks and door chimes. The doors keep trying to unlock and the dome lights come on while driving down the road. Dodge ram 2500 cummins
GREAT VIDEO but 80% of cars you cannot backprobe the ecu without disassembly cause most manufacturers use that swing lock connector and such. Just probe the wire and a dab of liquid electrical tape. If been a tech 15 years.
I have a mass air flow sensor with these reference voltage is terminal A 11.84v B .005v C .006v D.022v this is on a 1994 f-150 5.0l the ignition switch does nothing when turned to start already replaced the ignition switch and neutral safety switch shotgun affect it does have spark at the coil and the spark plug and the coil tan wire flashing with a test light showing coil control Do you think the pcm is bad or not
Hello, I am new to this. I have a truck and I have replace the engine with a rebuilt. So now it has a no com with the ecm. I checked all my 5volt reference all good and my computer ground is good and I got good power to the computer. And yes I have replace the computer. And it still no start no com with the ecm All my fuses are good, relay are good. Where could I go from here? Help
Thank you for this lesson. I went to school to be a tech and trying to deepen my knowledge while working on my car. Are there any books or other resources that go in depth about DTC diagnosis like the one you’re describing? Once again thank you🙏
Can you show us how to read, understand, and comprehend electrical wiring diagrams, please? There are alot of viewers with mental learning disabilities and they really want to learn how to read, understand and comprehend electrical wiring diagrams but they struggle to learn it because it has to be broken down like if it was being taught to kids so the minds of the mental learning disabled can get a good grasp on it and comprehension. I like how you teach in this video because i truly feel like it would help the mental learning disabled learn because your teaching style makes it easy to understand and comprehend to where the knowledge can be applied with confidence.
My car seem to have a separate +5v power pin slot on the PCM/ECM connector for each individual sensor. I have a Accelerator Position Sensor Signal Circuit Low Input, does this mean Short-to-Ground?
Im admit stumped on one never am I specially fords. But I have a P06A7 vref B backprobe I have 5v dtc is CMDTC runs like crap came here for help per usual lol
Wow best application I gave ffound! Please help l have 2001 xj cherokee check engine light illuminated even though both of my readers have no mil light on and zero codes. Also reads ready for smog check. Is this a short? Where should I look ?
Mitsubishi eclipse 2000 With key on engine off I'm testing the 5v reference at the connector with the connector disconnected! Am I doing it right. I only get 1.5 volts! I have codes for crank sensor and cam sensor! Appreciate the help!
Wow iam impressed i should watch this video 3 times a week You are really good at explaining Thank you so much and keep up the good work Ps: i just subscribed i hope to see more great videos
Hi, wanted to say great video, i had a question, i have a 2012 gmc acadia 3.6 with 145,000 miles got ripped off on this car started giving me problems 2 days after i bought it. Goes into limp mode and stalls sometimes and tgen sometimes its normal. Any advice what i should look at.
My 5v reference wire shows 12v when back probing with the pcm connected. If I disconnect the pcm it drops down to 0v. I thought it was a short to power but if that was the case wouldn’t 12v always be present regardless if the pcm is connected or not?
Good night my I just watch you video on RUclips about computer but I am working on land rover freelander 2005 with no spark no injector pulse change crank sensor and Cam sensor still no spark or injector pulse just need you help thanks much
Hello friend, my name is Shahram, I live in Iran I am an automotive electrical engineer who worked on cars for 18 years, but I am very interested in progress, but in our country it is not possible. Can you help me to progress?
Great video! I have a Silverado with 2.5 volts on my 5 volt ref. maf and map 2.5 volts and truck doesn't start. Can a bad sensor cause a 2.5 volt at the 5 volt ref any suggestions appreciated thanks
I have no check engine light but when i put scaner showes crank sensor and brake pressure. The brake sensor is good. Crank sensor i put new still pops up. I ve replaced so many parts like trottell body tps,mass airflow, coolent temp, accelerator pedal sensor. Pcv, and had torque converter rebuilt, still car dont run right any help would be appreciated
What if you have 5 volts but sensor doesn’t read on scanner , it was reading when I installed new Maf map sensor then worked all of sudden stop reading anything
1991 Jeep 4L put a CSP because it checked bad. Put a new one on (I checked the new 1 showed good) no start. Checked the new 1 after and now tested bad . ? Thanks for any help
Nissan Murano with no accelerator pedal response . one of the two acc pedal( sensor 1 ) sensors with no 5 volts. the ground wires are ok .no cut in all wires. I changed used ECU then checked 5 v of the sensor 1 but nothing new ( no 5 v) .
Did you say how to troubleshoot the signal/ground circuit shorted? I listened 3 times and still don't know how to check for that other than to see melted wires. My guess is to check the continuity from each signal wire at the harness side to the battery. Much like you suggested on 3.
in the next step for your diagnostic when you are talking about an open before the split of 5V reference , the reference pin at the PCM should give us the 5v on the meter ! am i wrong ? thanks
Hi, i have 2007 fj cruiser. The engine light are on and others light too. Have P-2743 code transmission fluid temperature or B circuit high. I change the transmission oil, filter and the whole wire thar has two tft sensor and the light continue on. How I can verify the wires and the codutuivity if the cables are under the car and the computer are inside the car.
hi i have a 2009 ford fiesta 1.6 tdci,i was driving it last week with no problems,then out of the blue a cog light came on which i have been told is the pcm light,the car died and wouldnt start for around 5 mins,eventually got it running and got it home,a friend plugged it in and a p0698 code came up,he said it was throttle pedal,so replaced that also put a new fuel filter after a day or 2 same thing happend,it wouldnt start so i put a forscan on it turned the pcm light off and it started,after 2 hours cut out again so i unplugged egr and it run fine for 2 days then the light came on again even with the egr unplugged,it has no problem starting but once that pcm light comes on the car will not start until i plug forscan into it and clear the p0698 code,is there anyone out there who can help it says sensor reference voltage c circuit low additional fault symptom circuit voltage below threshold......thanks in advance,jon
Your second step is confusing. If the pcm is supplying the 5 v ref out to the sensors and you back probe at the pcm then a break in the 5v ref wire leaving the pcm won't affect your readings. In order to do step 2 you would have to check 5v ref at each sensor in order to see a broken wire. Or maybe I'm misunderstanding you.
@ 9:14 if you have continuity between ground and battery ground then your grounds are good. NOT TRUE! This assumption could produce a false diagnosis. Seen it many times. You want conductivity in your wiring. The only way to see this is through voltage drop testing. It’s too easy to not do. You shared some great tests but I was disappointed when you suggested continuity testing.
Your statement is true, however this video is called electrical diagnosis 101, running a load test on circuits is a more accurate way to verify that a circuit is good, but many people will not have that capability and a simple continuity check is a good first step. If you eliminate all other possibilities and you still suspect a circuit issue then I would absolutely perform a load test, but it's not going to be my first step.
I finally understand it thank you for putting this out . I was struggling with trying to understand how a 12 volt system could have multiple 5volt references. I was like it would share the voltage. This helped a lot . Great teacher 👊🏻
Thanks for the video! I'm having an issue with my 2009 2500hd and have a 12v on the 5 volt reference circuit on the MAF. I have swapped a cammed LS3 into the truck and it ran mint after the factory truck ECU was tuned for the engine. Then I got poor idle and poor power and drivablity. P0102 code. Bad ground?
If you've got 12v battery power on a 5v reference circuit then you've got another voltage circuit shorted to that one. There should never be 12v on a 5v circuit. 👍
The pcm is reading the signal voltage coming back from the sensor. You may have either a short to ground somewhere on the signal circuit, or an internal short in the sensor itself that is pulling the circuit down. If there are multiple sensors on one circuit you can start by disconnecting them one by one to see if the circuit recovers. If you can isolate which sensor is pulling the circuit down then at least you'll have a starting point. 👍
I have a 5v reference problem all 4 5v reference are reading 5.01 to 5.03 high and it get all kinds of random codes and a shop told me it was a Ecm so got a new one had a Buick dealership program it and still have a problem and where do I find the wiring diagrams?
I'm chasing this in a dodge avenger 3.6 that got rained on and got a no start after. My 5v reference is only 3v and my throttle is unresponsive. Getting a bunch of codes.
@@Boomer21b shoot me a message on Instagram @reignited.tx with the VIN of the car and I'll see if I can find that out for you. Also put a list of the codes you're working with. 👍
Dang. After finding your channel and watching this video, I was really hoping to see more like this. I just replaced timing chains on a 3.6L GM (09 Acadia) and now I have a cam/crank out of sync code. I was very careful about the chains being right on every tooth. I know it probably jumped a tooth at the first startup, but I wanted to check sensors before I tore apart completely and recheck the chains and tensioners.
@@ReignitedAuto So I'm finding out! I also did the cam phasers and oil pump while I was in there, but who knows. Maybe one or more of the replacement phasers wasn't perfect, maybe the crank reluctor shifted, maybe a new tensioner isn't functioning properly, chains out of time despite my best efforts...but at least I can check the 5v circuit first. Thank you for this video.
I have a 2007 jeep grand cherokee Laredo 3.6 NAG1 TRANS,it has intimidating no start it starts great when it wants to,codes P0507,p2299,p0113,u0404,u1415,u1414,B212d ,I am going to run through your process today 07/12/21.
I have an o6 Silverado 1500. the radiator cooling fans come on high as soon as i start the truck and stay on, but as soon as i unplug the ac high pressure switch the fans work properly. but Ac will not work until i plug the pressure switch back. I am going to use this method to try to figure it out.
@@ReignitedAuto THANK YOU FOR REPLYING BACK. What gets me is both radiator fans will run on high even if the ac and heater are off. I leave to work in the morning, and the temp is 52F and both fans come on high as soon as I start up the truck and stay on until i shut the truck off. I've had 3 shops try to figure it out and paid to replace the PCM but the problem is still there . I have also had to replace the radiator fans because the motors went out due to the fans running all the time. What is a good resource for electrical diagrams? Thank you for your taking the time to help!!
How does a 5V signal should look like? I have an intermittent problem with my 2013 Durango V6, going occasionally into limp mode and throwing a bunch of codes related to 5V circuits. I already replaced all sensor, the PCM and tested the harness for shorts. I observe some downward spikes, is it normal? This is the behavior that I observe: ruclips.net/video/tMlXGUC9aEY/видео.html
Absolutely great lesson. I'm having probs and will use your instructions to hopefully solve the issue. Virgin all original 2001 Focus no crank no start shutoff while driving dashes for odometer display smell of burnt electrical inside car.
Excellent job. The PCM sends out 5v to each sensor and reviews the reply/returning voltage. Based on the returning voltage, the PCM determines something is wrong and issues a DTC & turns on the CHECK ENGINE LIGHT so the driver takes it to the dealer and gets fleeced.
@@ryanramlochan1504 Not super familiar with a bias voltage myself. It seems to similar in operation to reference voltage, but there might be small differences I'm not aware of.
Im really glad i found this video, im going to use it on my stock 1989 2.3 mustang. I accidentally put the sensor in backwards because someone at the shop broke the connector, im not mad its old it happens. Then i tapped the battery together on the positive and negative when I was tightening the battery back up. Now i have to no acceleration issues a while later. I serviced the whole car so yes thank you for this!!!!!!!!!!
Buddy....Excellent video! I wish you would make more diag videos on electrical. Solid info. Ive been doing this 15 yrs and still was struggling with5v. The way you explained some of, just hit me all of a sudden. Now kinda feel like a dipshit.
Hi there. I own a Vw Polo Gt Tdi 1.6, my car has been throwing a 00538 reference Voltage-Open Circuit error in Central Electronics and even the air conditioner has been getting cut off randomly. I had sent the car to VW workshop to fix the said code and they checked the Climatronic, BCM, Reference Voltage Fuse and wiring and they all were fine, but still the fault code reader was flashing 00538 error, after which the master technician hooked a battery charger to the battery and erased the code and it didn't appear again, which it used to after turning the ignition off and then on. The Technician said that it is a bad alternator, but then the battery voltage is at 12.8 when the car is off and when the car is turned on without A/c. it shows 13.9-14 and when the A/c is turned on it shows 13.78. There's no issue with starting the car, no battery icon on instrument cluster, nothing, but the fault code won't go.
I'm not an auto electrical diagnostic technician but i am an electronic technician turned marine electrician - seeking to enter the automotive electrical field...at home. I simply want to mention that this instruction makes a whoooole lot of sense to me.
GREAT WAY of explaining!
Having 5 volt reference issues after doing head gaskets etc,. My $ is on bad wire cuz I can clear codes and runs fantastic. Shut it down,goes into limp mode.
Solid, clear explanations on how to diagnose the problems in a 5-volt reference system. You have spent some of your time in the automotive industry being an instructor. :)
Thanks gene! Actually being an instructor was a long term goal of mine, but I found that youtube allows me to reach such a broader audience that I really enjoy it! Thanks again for all your positive comments on the videos. 👍
I never knew you could wear a tie and teach about automotive electrical so well. I am so impressed. Thank you for the simplicity.
Appreciate you watching!
lol😄
Care Bears & My Pony rainbow T-Shirt would have quite an impression as well. Very respectable as we don't see men dressing up these days more of the unkept pubic hair beard dirty hippy tats all over look is common.
Well he is teaching theory and great at it
Great white board usage professor!
I aim to please! 😄 Thanks for watching Tom! 👍
This is the best explanation and study guid to understanding 5v references, thank you for keeping it SIMPLE. I will subscribe
Fleet mechanic here. Excellent video. Just about every mechanic I know struggles with 5 volt supply and j1939 problems , including myself. Just applied the first step to a Cummins diesel I was working on today. I found the problem in 5 minutes. Same approach I use for j1939 issues , just never used it for 5 volt supply. Again, excellent video.
I particularly like the step by step writing results down. Easy to get lost and frustrated if you don’t.
Spoken by the man himself! 👍
Its true.....thats the way to diagnose an electrical fault.......i got more or less same on my 2001 JGC WJ L6.... (i still have to fix the engine injectors wiring harness .... but here on the island its kind of difficult to find a good one to replace it).... but as a matter of fact a good procedure for diagnosting those electrical issues....keep it up ... nice job bro..... and bye the way .. have a merry chrismas......👊🏻👍🏻
When pin is in wire connector at PCM, shouldn't there be power?.or does 5v comes to PCM,?,thx
Power comes from the pcm, so it should show voltage, but if somewhere downstream the circuitis grounded or shorted to another circuit it will read 0 volts 👍
Thank-you so much, excellent board lessons and tool recommendations!
Thanks for the video! I am dealing with a rainstorm damaged system. Replaced fuseblock, gem, pcm,alternator, starter, and starter relay. Pcm was the last purchase and was not necessary. I replaced the alternator due to high frequency signal disrupting the CPS. After replacing I still have other codes for high voltage/malfunction for a few circuits. Turns out they all share 5v ref. All wires have .0, .1 ohms resistance. All wires show 5.05 volts. Chasing this down has driven me partially insane still love this stuff though.
Awesome video, how could I learn more about 5V reference circuits? Also, is reference voltage the same as signal voltage? Thanks!
The reference voltage is the voltage that comes into the sensor, the signal voltage is what comes out of the sensor and goes to the PCM 👍
Shotgun approach? It's called the "Parts Cannon" dude. Geez... Good video
"Fire in the hole!" 😄
Finally, someone that took the time to share this in a simple way to understand. Really really, THANK YOU. Now, I can finish up my 99' Suburban with a Crank but won't Start issue since about 3 years... I will update more later. God bless you!
Thanks for watching Jose!
Nice logical walk through.
For me it’s nuts and bolts all day. Electrical? No way 😂
Nice simple electrical explanation. I hate electrical!! I'm the "shotgun" guy. Start replacing sensors and hope it's the right one 😁. I can't tell you how many times I've heard people say it's the PCM. Mechanics as well without even doing any testing. 🤦
Please make a video on speed sensor to pcm and from pcm to components.. No speedometer to rule out pcm two wire sensor
Thank you professor
Thank you for this video I’ve been trying to diagnose the same issue with my own nine Sierra and I’ve been so lost because I don’t understand the system. This really helped and I will go through all these steps tomorrow.
Thank you so much for uploading this simplified instructional video, absolutely AWESOME, it has helped enormously with a very difficult job we had in our shop,but after watching this video, we nailed it rather rapidly, no better sight than the rear number plate of that eyesore disappearing into the sunset with a happy customer 🙂please post more, it most certainly deserves at least a Billion thumbs up. Bless
So glad it helped! You're absolutely right, nothing better than watching a problem child go out the door 👍
@@ReignitedAuto Thank you so much for your kind response, interaction often brings forth mutual respect, we believe your systematic and progressive approach with key points in a simplified way aids better understanding,no long winding excessively technical droning makes for a truly innovative learning experience, your channel is vastly underrated, we shall be seeking out all other videos of yours very soon. my father used to say to me; 'There is always something to learn from everyone regardless of our own personal skill level or knowledge,to show gratitude is the very least we must do,and reflects upon our character and upbringing'. may you go from strength to strength,with greater recognition, as all good intention has never ever gone wasted or fell on deaf ear's, THANK YOU 😇🙂👍
Something weird about a guy in a tie teacher electrical diag. 😁
Trying to class this place up a bit! 😄
Thank you so much for explaining this so simply. Quick question though. So what voltage readings will you get if a VREF and signal circuit touch, if a VREF and ground circuit touch, and a signal circuit and ground circuit touch for example # 6? Thank you again.
MY code reader os saying PCM isnt equipped. im guessint it is a bad PCM. not the ECM next to the fuse box, but in the driver side wheel well the PCM. a 2003 Caravan. It was confusing for awhile because people anf\d articles are calling the ECM, the PCM.
This is the Best ever diagnostic video, I have ever seen. Awesome instructor! Thanks.
Can you dissect a wiring diagram for a 2006 Dodge Ram truck 2500 door locks and door chimes. The doors keep trying to unlock and the dome lights come on while driving down the road. Dodge ram 2500 cummins
GREAT VIDEO but 80% of cars you cannot backprobe the ecu without disassembly cause most manufacturers use that swing lock connector and such. Just probe the wire and a dab of liquid electrical tape. If been a tech 15 years.
I have a mass air flow sensor with these reference voltage is terminal A 11.84v B .005v C .006v D.022v this is on a 1994 f-150 5.0l the ignition switch does nothing when turned to start already replaced the ignition switch and neutral safety switch shotgun affect it does have spark at the coil and the spark plug and the coil tan wire flashing with a test light showing coil control Do you think the pcm is bad or not
Does all the sensors with common wire have common colour wire to computer in different brands of cars
Hello, I am new to this. I have a truck and I have replace the engine with a rebuilt. So now it has a no com with the ecm. I checked all my 5volt reference all good and my computer ground is good and I got good power to the computer. And yes I have replace the computer. And it still no start no com with the ecm All my fuses are good, relay are good. Where could I go from here? Help
Thank you, very helpful. I was testing with my sensors plugged in!
DIY automotive electrical testing tools you can build yourself:
ruclips.net/video/wkUGeFYLgoo/видео.html
What causes a grd voltage in all 5v circuit.pcm? Every pin .limp mode?
Thank you for this lesson. I went to school to be a tech and trying to deepen my knowledge while working on my car. Are there any books or other resources that go in depth about DTC diagnosis like the one you’re describing? Once again thank you🙏
Can you show us how to read, understand, and comprehend electrical wiring diagrams, please? There are alot of viewers with mental learning disabilities and they really want to learn how to read, understand and comprehend electrical wiring diagrams but they struggle to learn it because it has to be broken down like if it was being taught to kids so the minds of the mental learning disabled can get a good grasp on it and comprehension. I like how you teach in this video because i truly feel like it would help the mental learning disabled learn because your teaching style makes it easy to understand and comprehend to where the knowledge can be applied with confidence.
My car seem to have a separate +5v power pin slot on the PCM/ECM connector for each individual sensor. I have a
Accelerator Position Sensor Signal Circuit Low Input, does this mean Short-to-Ground?
My 5v is fluctuating from 4v-6v going as low as 3.2 while running.. is this normal?
Im admit stumped on one never am I specially fords. But I have a P06A7 vref B backprobe I have 5v dtc is CMDTC runs like crap came here for help per usual lol
Wow best application I gave ffound! Please help l have 2001 xj cherokee check engine light illuminated even though both of my readers have no mil light on and zero codes. Also reads ready for smog check. Is this a short? Where should I look ?
Mitsubishi eclipse 2000
With key on engine off I'm testing the 5v reference at the connector with the connector disconnected!
Am I doing it right.
I only get 1.5 volts!
I have codes for crank sensor and cam sensor!
Appreciate the help!
Wow iam impressed i should watch this video 3 times a week
You are really good at explaining
Thank you so much and keep up the good work
Ps: i just subscribed i hope to see more great videos
Thank you for the kind words and I appreciate you watching! 👍
Hi, wanted to say great video, i had a question, i have a 2012 gmc acadia 3.6 with 145,000 miles got ripped off on this car started giving me problems 2 days after i bought it. Goes into limp mode and stalls sometimes and tgen sometimes its normal. Any advice what i should look at.
My 5v reference wire shows 12v when back probing with the pcm connected. If I disconnect the pcm it drops down to 0v. I thought it was a short to power but if that was the case wouldn’t 12v always be present regardless if the pcm is connected or not?
Good night my I just watch you video on RUclips about computer but I am working on land rover freelander 2005 with no spark no injector pulse change crank sensor and Cam sensor still no spark or injector pulse just need you help thanks much
When testing, is the vehicle accessories on engine off ?
Engine is always off, but whether the key is on or not depends on whether you are doing a voltage test or a continuity test.
Hello friend, my name is Shahram, I live in Iran
I am an automotive electrical engineer who worked on cars for 18 years, but I am very interested in progress, but in our country it is not possible. Can you help me to progress?
Thanks your great now i know how to check my computer for 5 volt reference to know if my computer is bad Thanks God Bless You
Great video! I have a Silverado with 2.5 volts on my 5 volt ref. maf and map 2.5 volts and truck doesn't start. Can a bad sensor cause a 2.5 volt at the 5 volt ref any suggestions appreciated thanks
I have no check engine light but when i put scaner showes crank sensor and brake pressure. The brake sensor is good. Crank sensor i put new still pops up. I ve replaced so many parts like trottell body tps,mass airflow, coolent temp, accelerator pedal sensor. Pcv, and had torque converter rebuilt, still car dont run right any help would be appreciated
What if you have 5 volts but sensor doesn’t read on scanner , it was reading when I installed new Maf map sensor then worked all of sudden stop reading anything
1991 Jeep 4L put a CSP because it checked bad. Put a new one on (I checked the new 1 showed good) no start. Checked the new 1 after and now tested bad . ? Thanks for any help
Nissan Murano with no accelerator pedal response . one of the two acc pedal( sensor 1 ) sensors with no 5 volts. the ground wires are ok .no cut in all wires. I changed used ECU then checked 5 v of the sensor 1 but nothing new ( no 5 v) .
Did you say how to troubleshoot the signal/ground circuit shorted? I listened 3 times and still don't know how to check for that other than to see melted wires. My guess is to check the continuity from each signal wire at the harness side to the battery. Much like you suggested on 3.
What sensors does the 7.3 use the the 5v reference my truck pcm no communication was working but now nothing but will not start
i cant watch you explain in that suite and tie , plzz be in mechanic way 😹😹 that will give us more vibes !!!!!!
in the next step for your diagnostic when you are talking about an open before the split of 5V reference , the reference pin at the PCM should give us the 5v on the meter ! am i wrong ? thanks
Hi, i have 2007 fj cruiser. The engine light are on and others light too. Have P-2743 code transmission fluid temperature or B circuit high. I change the transmission oil, filter and the whole wire thar has two tft sensor and the light continue on. How I can verify the wires and the codutuivity if the cables are under the car and the computer are inside the car.
wtf is a back prode.....how do you actually do it you said how to do it, but I've never done it, so I still don't understand
hi i have a 2009 ford fiesta 1.6 tdci,i was driving it last week with no problems,then out of the blue a cog light came on which i have been told is the pcm light,the car died and wouldnt start for around 5 mins,eventually got it running and got it home,a friend plugged it in and a p0698 code came up,he said it was throttle pedal,so replaced that also put a new fuel filter after a day or 2 same thing happend,it wouldnt start so i put a forscan on it turned the pcm light off and it started,after 2 hours cut out again so i unplugged egr and it run fine for 2 days then the light came on again even with the egr unplugged,it has no problem starting but once that pcm light comes on the car will not start until i plug forscan into it and clear the p0698 code,is there anyone out there who can help it says sensor reference voltage c circuit low additional fault symptom circuit voltage below threshold......thanks in advance,jon
I need some one Know how to Remplace fuise box On 1970 chevy Monte carlo
This video is straightforward, systematic, concise, and thorough.👌
t?he PCM needs a 12v feed to give us a 5v reference . so in my opinion the fault can come from the fuse box. am i missing something ?
Hey teacher, you looks like lowyer!
😄
Thank you! I will be coming back to this video everyday!
Appreciate you watching!
iit meant that pcm send the signal to sensor When signal lose (5v). PCM will work
What about whem it's not the a side it's the d/e voltage correlation, even after replacing pedal and throttle body
Thank you .I've been looking just for this info.You explain this so well.
I appreciate that, thank you for watching!
I need some body to Remplace the fuse box on my 1970 Monte carlo I in Modesto Cal tex me
Your second step is confusing. If the pcm is supplying the 5 v ref out to the sensors and you back probe at the pcm then a break in the 5v ref wire leaving the pcm won't affect your readings. In order to do step 2 you would have to check 5v ref at each sensor in order to see a broken wire. Or maybe I'm misunderstanding you.
Thank you for showing us how to be a better technician.
Where do u get wire diagrams... ? That's the problem
thanks, I get benefits from systematic expkanation
@ 9:14 if you have continuity between ground and battery ground then your grounds are good. NOT TRUE! This assumption could produce a false diagnosis. Seen it many times. You want conductivity in your wiring. The only way to see this is through voltage drop testing. It’s too easy to not do. You shared some great tests but I was disappointed when you suggested continuity testing.
Your statement is true, however this video is called electrical diagnosis 101, running a load test on circuits is a more accurate way to verify that a circuit is good, but many people will not have that capability and a simple continuity check is a good first step. If you eliminate all other possibilities and you still suspect a circuit issue then I would absolutely perform a load test, but it's not going to be my first step.
What about a “low voltage sensor “D” ? Anybody?
It’s just hard to trust any macanic wearing a tie
you're not wrong.... 😄
You make it sound almost easy
As I was editing the video I was thinking, "does this even make sense?" 😂
I finally understand it thank you for putting this out . I was struggling with trying to understand how a 12 volt system could have multiple 5volt references. I was like it would share the voltage. This helped a lot . Great teacher 👊🏻
Thanks for watching i appreciate it!
This is great, do you have a video on crank but no start
Thanks for the video! I'm having an issue with my 2009 2500hd and have a 12v on the 5 volt reference circuit on the MAF. I have swapped a cammed LS3 into the truck and it ran mint after the factory truck ECU was tuned for the engine. Then I got poor idle and poor power and drivablity. P0102 code. Bad ground?
If you've got 12v battery power on a 5v reference circuit then you've got another voltage circuit shorted to that one. There should never be 12v on a 5v circuit. 👍
Great job man! Easy to follow, A friend of mine has a 06 duramax doing the same thing, Thanks for sharing your knowledge, Cheers 🍻
Thanks for watching Zeke! 👍
So I have 5v coming from the pcm but in the scan tool it's reading 0. All the sensors have 5v to them... scratching my head
The pcm is reading the signal voltage coming back from the sensor. You may have either a short to ground somewhere on the signal circuit, or an internal short in the sensor itself that is pulling the circuit down. If there are multiple sensors on one circuit you can start by disconnecting them one by one to see if the circuit recovers. If you can isolate which sensor is pulling the circuit down then at least you'll have a starting point. 👍
Very good quick and simple explanation, new sub here
I appreciate it my man 👍
I have a 5v reference problem all 4 5v reference are reading 5.01 to 5.03 high and it get all kinds of random codes and a shop told me it was a Ecm so got a new one had a Buick dealership program it and still have a problem and where do I find the wiring diagrams?
5.3 volts is not a problem
Extremely helpful video. Well done!
Thanks man! 👍
If you do the testing and come down to a pcm, start over. In 25 years of doing diagnostics every day I have changed 3 pcm’s
I have p2138 code 4 shops 1300$ and still have the issue pedal throttle body and pigtail replaced, now shop says maybe a bad ecm,
I'm chasing this in a dodge avenger 3.6 that got rained on and got a no start after. My 5v reference is only 3v and my throttle is unresponsive. Getting a bunch of codes.
Ouch. Those situations can be some of the most difficult to diagnose. Good luck to you!
@@ReignitedAuto thanks, not a whole lot of info available. I know it's 5v circuit "B" but I can't find a definitive list of what's on circuit B.
@@Boomer21b shoot me a message on Instagram @reignited.tx with the VIN of the car and I'll see if I can find that out for you. Also put a list of the codes you're working with. 👍
Dang. After finding your channel and watching this video, I was really hoping to see more like this. I just replaced timing chains on a 3.6L GM (09 Acadia) and now I have a cam/crank out of sync code. I was very careful about the chains being right on every tooth. I know it probably jumped a tooth at the first startup, but I wanted to check sensors before I tore apart completely and recheck the chains and tensioners.
Those engines are notorious for that nonsense! i've done a couple on some Suzuki vehicles that use that GM engine weirdly. Always a pain in the butt.
@@ReignitedAuto So I'm finding out! I also did the cam phasers and oil pump while I was in there, but who knows. Maybe one or more of the replacement phasers wasn't perfect, maybe the crank reluctor shifted, maybe a new tensioner isn't functioning properly, chains out of time despite my best efforts...but at least I can check the 5v circuit first. Thank you for this video.
I have a 2007 jeep grand cherokee Laredo 3.6 NAG1 TRANS,it has intimidating no start it starts great when it wants to,codes P0507,p2299,p0113,u0404,u1415,u1414,B212d ,I am going to run through your process today 07/12/21.
I have an o6 Silverado 1500. the radiator cooling fans come on high as soon as i start the truck and stay on, but as soon as i unplug the ac high pressure switch the fans work properly. but Ac will not work until i plug the pressure switch back. I am going to use this method to try to figure it out.
John that's actually normal if your a/c is on, or the vehicle is in defrost mode, the fans will be on high.
@@ReignitedAuto THANK YOU FOR REPLYING BACK. What gets me is both radiator fans will run on high even if the ac and heater are off. I leave to work in the morning, and the temp is 52F and both fans come on high as soon as I start up the truck and stay on until i shut the truck off. I've had 3 shops try to figure it out and paid to replace the PCM but the problem is still there . I have also had to replace the radiator fans because the motors went out due to the fans running all the time. What is a good resource for electrical diagrams? Thank you for your taking the time to help!!
Replace coolant sensor and temperature sensor and check all wiring to those components
Who ever disliked this video problably didnt like to see you in a tie
You're probably right 😄 I kind of want to do more videos like this, but I understand it's not for everyone. 👍
How does a 5V signal should look like? I have an intermittent problem with my 2013 Durango V6, going occasionally into limp mode and throwing a bunch of codes related to 5V circuits. I already replaced all sensor, the PCM and tested the harness for shorts. I observe some downward spikes, is it normal? This is the behavior that I observe: ruclips.net/video/tMlXGUC9aEY/видео.html
Shirt and tie on, excellent 👍
Very methodical and best explanation I have seen so far.
Appreciate you watching! 👍
Absolutely great lesson. I'm having probs and will use your instructions to hopefully solve the issue. Virgin all original 2001 Focus no crank no start shutoff while driving dashes for odometer display smell of burnt electrical inside car.
Excellent job. The PCM sends out 5v to each sensor and reviews the reply/returning voltage. Based on the returning voltage, the PCM determines something is wrong and issues a DTC & turns on the CHECK ENGINE LIGHT so the driver takes it to the dealer and gets fleeced.
Never knew what a reference voltage was till I saw your video,very good explanation
Thanks for watching!
@@ReignitedAuto do 2 pin cam an crank sensor have reference voltage as well
@@ryanramlochan1504 Nope, those generate a a voltage signal by metal teeth passing near the magnetic end of the sensor, just like wheel speed sensors.
@@ReignitedAuto thanks just one more thing.whats a bias voltage and the simplest way to understand it
@@ryanramlochan1504 Not super familiar with a bias voltage myself. It seems to similar in operation to reference voltage, but there might be small differences I'm not aware of.
Im really glad i found this video, im going to use it on my stock 1989 2.3 mustang. I accidentally put the sensor in backwards because someone at the shop broke the connector, im not mad its old it happens. Then i tapped the battery together on the positive and negative when I was tightening the battery back up. Now i have to no acceleration issues a while later. I serviced the whole car so yes thank you for this!!!!!!!!!!
KNOWLEDGEABLE
Buddy....Excellent video! I wish you would make more diag videos on electrical. Solid info. Ive been doing this 15 yrs and still was struggling with5v. The way you explained some of, just hit me all of a sudden. Now kinda feel like a dipshit.
Great lesson...thanks!
Hi there. I own a Vw Polo Gt Tdi 1.6, my car has been throwing a 00538 reference Voltage-Open Circuit error in Central Electronics and even the air conditioner has been getting cut off randomly. I had sent the car to VW workshop to fix the said code and they checked the Climatronic, BCM, Reference Voltage Fuse and wiring and they all were fine, but still the fault code reader was flashing 00538 error, after which the master technician hooked a battery charger to the battery and erased the code and it didn't appear again, which it used to after turning the ignition off and then on. The Technician said that it is a bad alternator, but then the battery voltage is at 12.8 when the car is off and when the car is turned on without A/c. it shows 13.9-14 and when the A/c is turned on it shows 13.78. There's no issue with starting the car, no battery icon on instrument cluster, nothing, but the fault code won't go.
with this your tutorial, i feel inside college of auto wiring already
Appreciate you watching Charles!