Mine is stuck in safe mode but I never had a dead battery or replace the battery and the keys were working perfect all of a sudden it is just stuck in safe mode and it only has one code that says lost communication with immobilizer . I'm having trouble finding where the immobilizer unit even is located. I would like to get a new one and install it myself and then tow it to the dealer who said they can program my existing keys to the new mobilizer for $220. Has anyone ever had this problem? Suddenly goes into safe mode for no reason and lost communication with immobilizer. Do you think this would fix it and where is the immobilizer actually located??
@@DiscreetNYC yes take spark plugs out in turn car over with them out to get all the extra fuel out of the cylinders also wipe the spark plugs off if there wet put everything back together in keep turning the car over until it starts my car was just flooded idk how but every time it rain there a good chance it will happen but I just keep turning it over it should start eventually if not check relay box make sure there’s no sign of moisture in there if there isn’t then relays isn’t the problem bc I thought it was my relays in ended up ordering sum In didn’t even need them because my car ended up starting it may get aggravating from turning the engine over for so long in it still not start but just be patient with it get you a battery booster so yours won’t go dead in just keep turning it over hope this helps if your having this problem
@@pmfkeim6330swapped the spark plugs and the car drove for about an hour. I found a bunch of water in the relay area underneath the ECU. I wonder where I can find those connectors
I have a no crank and the fuel pump goes off and on for a few seconds while trying crank. It may do it with just turning the ignition on but would need to test again to verify. Any thoughts? Possibly the same relay?
You mentioned no crank? Do you hear the engine crank when you have the key in start position? If you don’t hear the engine. I would start checking the power and ground at the starter motor. If you have a crank no start I would start off with a full system scan with a good scan tool first. See if you have the same trouble codes as mine. Hope it helps 🙏
No crank whatsoever. I just don't recall if the pump does its off and on thing when you turn the ignition on or when you try and actually start it. Either way it surges the pump off and on and absolutely no crank. All lights are coming on as usual when ignition is on.
@@whatsnext8825 🤔 I think it's normal to hear the prime for few sec when you have the key ON. Since you don't have crank at all. I would start looking into STARTER MOTOR CIRCUIT. Check power and ground at the starter. And also pay attention to the security light as well if there is any. because it might be car security system. (Try another key) If those doesn't work, You probably need to do a full system scan with a good scan tool. As it might give you some direction diagnosing this issue. Also, there is a lot of modules in these vehicles. Hope it helps.
@@whatsnext8825 Did you solve? I have same problem on my 2008 A4. Good battery. It was acting up a bit starting one day, and on my last errand, wouldn't start at all. Only a click.
I have the same problem on my b8.5. S4 it cranks like the video but no start I found two 646 relays rusted badly and the 645 relays had corrosion on them so I got some spare 643 relays swap in the replacement of the 645 and got two used 646 but still no start also no power to fuel pump fuse? When I scan it it says Ecm relay high
I think this is exactly my problem. Buying the relay now
Same problem, i changed 2 batteries 🔋 😂
Excellent video bro
Can’t find this relay from wells any links or part number , the one on the box doesn’t bring it up
Only if it was that easy..
Hey,
Do you know if there is a relay for the highbeam on the a4 b6?
Would this cause a parasitic drain aswell?
Whats the name of that relay
Mine is stuck in safe mode but I never had a dead battery or replace the battery and the keys were working perfect all of a sudden it is just stuck in safe mode and it only has one code that says lost communication with immobilizer . I'm having trouble finding where the immobilizer unit even is located. I would like to get a new one and install it myself and then tow it to the dealer who said they can program my existing keys to the new mobilizer for $220. Has anyone ever had this problem? Suddenly goes into safe mode for no reason and lost communication with immobilizer. Do you think this would fix it and where is the immobilizer actually located??
Hey mine flooded but i have absolutely no power at all. What could that be
I have a audo 2013 a4 same problem you think the relays are in the same spot?
I also have 2013 A4, let me know any updates
Mines turned out to be the timing belt
@@mandocash. Was check engine light on before you found out it was timing belt?
@@mysticaltrees7126yea i got out of work and it didnt want to start out of no where EPC light was also on
@@mandocash. Ah I see, for me it won't start but EPC light and Engine light are not on.
My b8 was perfectly fine I parked it then it rained after that it will not start
Same. Did you fix it?
@@DiscreetNYC yes take spark plugs out in turn car over with them out to get all the extra fuel out of the cylinders also wipe the spark plugs off if there wet put everything back together in keep turning the car over until it starts my car was just flooded idk how but every time it rain there a good chance it will happen but I just keep turning it over it should start eventually if not check relay box make sure there’s no sign of moisture in there if there isn’t then relays isn’t the problem bc I thought it was my relays in ended up ordering sum In didn’t even need them because my car ended up starting it may get aggravating from turning the engine over for so long in it still not start but just be patient with it get you a battery booster so yours won’t go dead in just keep turning it over hope this helps if your having this problem
@@pmfkeim6330swapped the spark plugs and the car drove for about an hour. I found a bunch of water in the relay area underneath the ECU. I wonder where I can find those connectors
Where can I find the connector for the relay?
I get mine at junk yards, simply clip them off at the yard and solder them back on to your wiring harness at home
I think this is also my car's problem, Some one can tell me what this relay's name in Diagram, J271? but it only have 4 pins, J271 should have 5pins.
1:37
I have a no crank and the fuel pump goes off and on for a few seconds while trying crank. It may do it with just turning the ignition on but would need to test again to verify. Any thoughts? Possibly the same relay?
You mentioned no crank? Do you hear the engine crank when you have the key in start position?
If you don’t hear the engine. I would start checking the power and ground at the starter motor.
If you have a crank no start
I would start off with a full system scan with a good scan tool first. See if you have the same trouble codes as mine. Hope it helps 🙏
No crank whatsoever. I just don't recall if the pump does its off and on thing when you turn the ignition on or when you try and actually start it. Either way it surges the pump off and on and absolutely no crank. All lights are coming on as usual when ignition is on.
@@whatsnext8825
🤔 I think it's normal to hear the prime for few sec when you have the key ON.
Since you don't have crank at all. I would start looking into STARTER MOTOR CIRCUIT. Check power and ground at the starter.
And also pay attention to the security light as well if there is any. because it might be car security system. (Try another key)
If those doesn't work, You probably need to do a full system scan with a good scan tool. As it might give you some direction diagnosing this issue. Also, there is a lot of modules in these vehicles. Hope it helps.
@@whatsnext8825 Did you solve? I have same problem on my 2008 A4. Good battery. It was acting up a bit starting one day, and on my last errand, wouldn't start at all. Only a click.
I have the same problem on my b8.5. S4 it cranks like the video but no start I found two 646 relays rusted badly and the 645 relays had corrosion on them so I got some spare 643 relays swap in the replacement of the 645 and got two used 646 but still no start also no power to fuel pump fuse? When I scan it it says Ecm relay high