2018 Silverado P2635 Code, Part 3: Could it finally, actually be fixed???
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- Опубликовано: 26 авг 2024
- Well, after the better part of 3 months of going back and forth to the dealership and being without our rig while they test and evaluate and replace stuff, we have gone the last 2 weeks and 1000 miles with NO check engine light - the first time in nearly a year we've gone that long without that stupid light coming on! Here's to hoping they finally got it right this time around.
Next up, some EFI Live tuning courtesy of Justin at Black Bear Performance! Stay tuned for more and if you haven't done it yet, hit that subscribe button to follow along!
Good video.
Very unsettling when Ranch Mechanic and the dealer can't figure out the problem without the amount of hassle you went through. Chevy needs to do more research and narrow down the P2635 code issue.
Fuel pump, i figured that. I've been having the same p2635 code on my 2017.
Yeah, pretty incredible that it took so many trips to the dealership before they finally admitted what was plainly obvious to me (and most of the rest of you guys, lol). Either way, once they replaced the in-tank pump everything was fine, and the problem hasn't returned in over 2 years now.
i know this video is 2 years old, but like in that time we had 2 chevys waiting for fuel pumps for 6 months. they were on intergalatic back order,. so maybe you started the back order lol.
I wouldn't be surprised in the slightest. 🤣
The image stabilization working well broski on the camera footage @5:00
I had my fuel pump replaced due too it leaking. Once it was replaced I now have check engine light on with a p0451 code.
@jasonsteiner8445 P0451 is your fuel tank pressure sensor. It's possible that it was damaged or unseated from the grommet during the fuel pump replacement, not plugged back in, or it has just failed due to age. The tank will likely need to be dropped to inspect it. If the CEL came on immediately after getting your truck back, I'd call the shop and see if they'll work with you on fixing it.
Which fuel pump tho high pressure or low pressure??
Shocked... not really those electric fuel pumps have been problematic for years.(I am a retired GM tech) 2 things i like to gripe about is 1. ETHANOL in the fuel, it is corrosive as hell shortens the life of everything in the fuel system. 2. Non OEM pumps, just stating facts on the ground from where I see it. They just don't hold up as well as the OE ones. I know that will trigger some. Just my 2 cents. I have a 2018 Silverado and have got rid of the AFM (a problem). And as a prevent defense I add 4oz. of MMO per 10 gallons of fuel to give some lubricity to the fuel that ethanol does not have.
Okay grumble time is over( time for my nap)
Totally agree with you on both points. Ethanol is murder on older vehicles, and any time I have to replace a fuel pump on a GM vehicle, it's either AC Delco or the Delphi equivalent. Parts store pumps are junk. Even with the supposed "lifetime warranty" some of them offer, I don't feel like dropping the tank on my truck every year or two to replace the stupid thing when it inevitably craps out. Buy once, cry once. Thanks for the comment Steve.
@@AllThingsMech Just woke up from my nap? To grumble again. I have never dropped the tank to change the fuel pump.( in a truck) Suburban is another story. Remove the left side bed bolts, loosen the right side bed bolts, remove the (3) 7mm screws from the fuel filler pipe at the gas door and jack up the bed. This always got me access to the top of the tank to change the fuel pump without to much cussing. Watching your channel gives me flashbacks. Keep up the great work on your channel. I will try to keep the grumble factor down.
Get your son to study 5 keys to safe driving smith system. It is here on you tube. A must for defensive driving.
P2635 is a circuit code for fuel pump nice that the warranty paid for it bout time they fixed it
I'm working on a 2011 camaro don't now much about it customer just bought it with code P2635 on it I noticed it's missing both catalytic converts exhaust is cut off and it has an air intake
I'm getting the same p2635 code. I have noticed that every once in a while it cranks much longer before starting. And engine almost died at a stop once. Would you recommend the intake fuel pump? Mine is the 2017 5.3 4x4 custom. Mine is performance tuned as well with s&b intake. Definitely custom tune is worth is!!!! Love your videos and subscribed!! Thank you!!
Thank you, Mike. Much appreciated! While your symptoms definitely sound more like the pump itself, there's really no way to be certain since the code is tied into so many systems...I'd hate to tell you to go for it and then have you toss $300+ in the toilet if it doesn't fix the issue, you know? If you decide are going to replace the pump, order an actual Delphi or AC Delco pump from a place like rockauto.com - the pumps you can buy locally are junk in my experience, and usually fail really quickly. Stay away from Amazon too...lots of fake "big name" parts circulating lately.
@@AllThingsMech I own a repair shop. We change out in tank fuel pump, and line pressure sensor for this problem all the time. Their are many different options for fuel pumps on these. I usually get it from the dealership, they look it up by vin #. But I do have one right now: 2017 chevy silverado 1500-high country with the 6.2L. Over last 3-mos I've change the fuel pump, pressure sensor, and fuel pump drive module. Runs good, but I'm still getting the P2635-frustrating.
@michael smith any chance that truck has the active grille shutters? If it does and you've replaced everything else, you may want to check into replacing them. I don't have a clue as to how or why they tie into the diagnostic flow chart for the 2635 code, but they were one of the first things the dealership replaced on my truck. Haven't had any issues with that code since they replaced the AGS assembly and the in-tank pump.
Sounds like the dealership keep throwing parts at it
Having this P2635 Code coming on Intermittenly 3x over past 10 months, recent one was today at Idle, Omph pulled code and the LIFT B1 AND B2 % is -14.84%. Looking at what would cause that low of a - % for those could possibly be a engine air filter? Had a K&N Filter installed, replaced with a normal dealer filter now. Any other thoughts? Not having any rough idle that I can tell either.
I have the same code but it only comes on when I start pulling a trailer would that be a fuel pump problem or something else
It's possible. I've found that these trucks are pretty sensitive to fuel flow rate - they'll run ok with a slight restriction, but will throw a code pretty easily. It's possible that you have a partially clogged pump sock in the tank; that would make sense if it only gets angry with you when you're pulling the trailer and are constantly needing higher flow rates to keep up with engine load. Are you noticing drivability issues/extended cranking times, or is it just throwing the code? It's also possible that it could have something to do with the active grille shutters if your truck has them...why those stupid things are on the same circuit as the fuel pump is a total mystery to me, but they are. Makes diagnosis a real pain. If you don't have a bidirectional scan tool that can check all of those components, I'd just take it to a shop for a diagnosis. It's pretty easy to get stuck firing the parts cannon at these things without finding the actual problem - it even took my dealership several attempts.
Cranking time when the light is on is longer then when the light is off. Drivability has no issue even when the light is on only issue with the light is on once I get around a 1/4 tank it wants to sputter and die when the light is on. I just got the truck a few weeks ago and the car fax shows that 2 fuel pumps have already been put in the truck over the last year. Could it be a evap leak that could cause any problems with the fuel demand?
I've got the same code thrown now on my 2016 Canyon 2.5L. my cheap OBDII reader tells me that it throws the code at 1mph, and I only noticed issues at slow speed/idle. It'll shudder a bit at stop lights occasionally and I noticed it's sluggish to accelerate/it takes more throttle to go, and my fuel mileage really suffers in stop/start low speed driving. On the highway I still get pretty close to normal mileage.
I'd love to fix it myself but from the sounds of it, it could be any number of things besides just the pump itself... Ugh. Maybe off to the dealer and unfortunately I'm beyond the warranty period.
From the symptoms it definitely sounds like a fuel delivery issue, and very well might be the pump. Can you pull any live data with your code reader? If you can, take a look at your Long Term Fuel Trim - the numbers should show a percentage in either positive or negative. They should remain close to zero, but will fluctuate quite a bit (usually about +/- 5%) as the engine tries to maintain a perfect air/fuel ratio. If the numbers are consistently high at idle, like +10% or more, it indicates a lean condition that the pcm is trying to compensate for by adding fuel (hence the higher fuel trim numbers; higher = injectors staying open longer and adding more fuel to get the proper AFR).
If you don't have access to live data, you can go to Napa and buy a relatively inexpensive fuel pressure test gauge for about $40, the Innova 3640 is the one I use. There should be a test port on your fuel rail with a cap on it (the fuel rail is what supplies fuel to the injectors, not sure how it's configured on the Canyon, but it usually looks like an aluminum bar next to your intake manifold). Unscrew the cap, and you'll see what looks like an oversized Schrader valve, like what you air up your tires with. The hose for the test gauge will screw right onto the port. Hook it up and turn the key on without starting the truck. The fuel pump should prime the system, and the gauge should read between 55-60psi. When you turn the key off it should hold most of the pressure but leak down very slowly...a 5psi drop every 2 seconds is considered normal. If the pressure is lower than 55psi or it doesn't hold pressure at all when you turn the key off (or both), your pump is on the way out.
I hope that's helpful. I'm dealing with a fuel pump issue on my 2007 Tahoe right now so all of this is fresh in my head. GM trucks are nice because they put that test port on the fuel rail - not every manufacturer does that, so it makes diagnosis on GM's much easier. Let me know if you have any questions, I'll do my best to walk you through it if you need help.
My issue on my 2018 GMC Sierra sounds exactly like yours and It’s throwing the same code. Bad news is I have already replaced the fuel pump and it’s still having the issue.
Had the same code on my 2016 Silverado, low voltage to "A" fuel pump. Had battery replaced and re-flashed at dealership. That was 10 months ago. Today, while driving, truck started to run poorly and finally died. I would wait ten minutes and was able to drive again. Note: voltage would drop significantly prior to shut down.
Pulled code P2635!
No check engine light came on.
Iam drinking a corona and watching videos to figure this out.
Will be in dealerships driveway tomorrow morning.
Wish me luck!
Funnily enough, I also ended up replacing my battery toward the end of last summer, and the code went away for a little while, but not long after came right back. I also saw the voltage dropping on my battery gauge, but apparently that is a normal function of these trucks - they will go into a kind of "alternator bypass" mode that electronically disconnects the alternator when it's not needed, and it will kick back on as necessary. My guess is that these pumps start drawing a ton of extra current when they go bad, so with the battery charged and the alternator running you were fine...but as soon as the alternator went into bypass mode there wasn't enough juice in the system to keep the pump running correctly and it finally died on you. By pulling over and waiting, the voltage in the battery probably had time to stabilize enough to run the pump again when you went to restart the truck.
Bottom line though, that fuel pump is probably toast! Best of luck man, hopefully your dealership will jump on this and get it taken care of.
@@AllThingsMech thank you for you response and time. I will post an update soon😎👍
Lmfao the fuel pump that is ridiculous
You will be good till the new fuel pump takes a circuit dump lmfao 🤣😂 sorry bro didn't mean to ginks ya
Ugh...I know man. Not sure what's up with this truck. We bought it as a dealer demo with 5k miles on it, and we have 65k on it now. I've had my suspicions since right after we got it that whoever was driving it that first 5k miles wasn't too nice to it. It's not really a lemon, but a bunch of little things that shouldn't be failing so soon are crapping out (wheel bearing at 38k, air box lid, active grille shutters, fuel pump, etc).
I love the truck but this stuff is getting a little irritating. Glad we got the extended warranty, but if that fuel pump takes a crap again I'm going to rip it out, leave the sending unit in place and run a walbro race pump with an in-line filter that I can actually service! 🤣
What would you recommend for a good in tank fuel pump replacement brand?
My car is throwing this code too , I have a 2019 camaro ss 10 speed , it has a lot of mods and it’s tuned for e85 , car still has stock fuel pump I don’t know if that’s starting to be the problem . I hope not cause I haven’t seen this problem on another Fbo E85 camaro . What do u think bro
That's a tough one brother. What kind of mods are you running? I wouldnt think you'd be outflowing the stock pump, unless you're running forced induction and/or a huge cam with different injectors. These fuel pump issues seem to be pretty common though across multiple GM vehicles. Do you have a fuel pressure gauge? If not, NAPA usually has them pretty cheap. There should be a port on the passenger side fuel rail to hook up to, I'd start there and see what your pressure is with both the key on/engine off (priming pressure, basically) as well as with the engine running at idle. It's not a sure bet, but it will at least tell you if the pump is making normal pressure at low loads.
Wow a week and a half
Could both those things play a part?
just to be clear, i thought you said 2018 truck, which would put the pump under the intake and not in the tank, or am i mistaken?
There are two pumps, but neither of them are under the intake. There is the high pressure direct injection pump which is on the driver's side valve cover (at least I'm fairly certain it's drivers side, been a minute since I've looked), and there's the in-tank pump that pushes fuel from the tank to the DI pump. The one in the tank is the one that failed on my truck.
Just had this code on 2018 Yukon Denali after a fill up at the gas station. Thinking it stirred some stuff up off the bottom and threw the code for low flow on pump. I had fuel pump fail on a 2001 GMC Sierra right after a fill up back in the day. I think it’s the same. Fuel pump needs replaced. Just bought this 4 days ago 🙄. Thoughts?
That's certainly possible, but with so many variables it's really hard to determine without looking at the truck in person and running down the troubleshooting list. Are there any other codes present? If not, your best bet would be taking it in and letting them run a diag on the fuel system. You could just replace the pump, but it seems like that has about a 50/50 success rate based on other folks I've talked to...and the good quality OEM pumps aren't cheap.
@@AllThingsMech yes did that and got the flow performance code on the pump. Wife was driving an hour away and never had any performance issues shut it off then started right back up still no issues. On the final leg of business trip home she said engine light went off 🤷🏻♂️
I’m having the same problem with my 2017 Silverado, I’ve replaced the fuel pump and the module and still the same code. Dealership says it’s the flow. I’m at a loss to ideas, any info i will gladly take!
Sorry to hear it, stuff like this is such a PITA. The path from the tank to the high pressure pump on the driver's side valve cover is relatively straightforward. It's possible that there is some kind of obstruction in one of the lines, but the filter sock built into the bottom of the in-tank pump should be more than enough to grab anything big enough to cause a blockage. I presume that you replaced the entire fuel pump/sending unit/filter as one assembly, so the filter should be new as well. Unless a fuel line is physically kinked/crimped/damaged from something coming up and hitting it, I honestly don't know. It's possible that there may be a restriction at the direct injection pump, although I think that would set a different code. Probably a silly thing to ask, but have you tried getting a fuel system service done? As far as I know, the only other place where the flow could get restricted would be at the injectors. It's a hail mary but it might be worth trying if you haven't already.
Was it the tank pump they replaced? Mine is doing the exact same…
Yes, it was the in-tank pump. Haven't had any trouble since they replaced it.
I'm confused, is this a vid about p2635 or a personal play by play
Maybe you just missed the part 20 seconds into the video where it says "go to 6:23 if you want to skip the drop off/pickup and initial drive". This is the last video in a series, there will be some talking and a recap. I haven't mastered telepathy yet, so how about you just watch the video and try to glean some useful information from it instead of complaining?
Hello friend, I already changed the fuel pump and I still receive the code p2635, what else could it be?

The dealership initially replaced my active grille shutter assembly, and told me it was on the troubleshooting flow chart for the P2635 code. You might talk to a local dealership and see if they can test it for you. Unfortunately I have no other insights into what could cause the code...I chased it for nearly a year before they finally replaced the pump.
So I changed all my injectors an high pressure fuel pump, I’m june, an now as off today the code came back on again😑
The high pressure injection pump mounted to your valve cover, or the transfer pump in the tank? I never needed to replace the injection pump, only the in-tank pump. If you haven't replaced that yet, I'd check it.
@@AllThingsMech I replaced the one on the motor
@ChanceChelios yeah, if you have a P2635 code you'll need to look at the pump in your fuel tank.
@@AllThingsMech it went away after I turned my truck off for awhile, but I did notice it came on after I used 86 fuel instead of high octane, since I have the 6.2, I also floored it to pass a vehicle an that’s when the light came on.
What up jb brother
What's going on man! How have you been?
@@AllThingsMech doing so so and how have you been brother
About the same...other than it being crazy hot here, I can't complain too much. Just keeping busy and getting stuff done.
@@AllThingsMech yeah its been 120 for last few weeks and we have a massive 200 plus Mike forest fire here in az we're I live its about 20 or so miles away is making it feel like 150 plus here
I have changed the fuel pump twice, Bosch, when that didn’t work, AC Delco, FPCM as well.
The original pump on the truck was Bosch. P2635 is still there.
Does yours have a gas cap? Mine don’t from factory. They said to get a 2 in pvc cap to keep the dust out.
Nope, ours doesn't have a cap, just the quick fill neck. We did actually buy a little rubber cap for it, but it never stays in place too long since the roads are so bad out here. I'm thinking about plunking down the extra money for the AC Delco locking cap, since it's supposed to sort of thread onto the filler neck. I doubt I'd ever actually lock it but maybe it would at least stay in place longer.
@@AllThingsMech they said that pvc will fit snug to stay in place but not too snug to where you can’t get it off. According to the Chevy tech.
Well, I'm actually on my way to home depot right now so I'll see what they have and give it a try. Thanks for the idea!
@@AllThingsMech let me know how it works. I’m actually under my pickup now changing the fuel pump. Lol
So, I ended up buying a 2" black ABS endcap, and it fits over the filler neck almost perfectly. Not a snug fit, but not too sloppy either. I might make a little modification to the inside to snug up the fit a bit more, but this is definitely a great solution. I'll probably end up making a Fast Tip Friday video about this, I'll be sure to give you a shout out in the video if I do. Thanks again man - hope the fuel pump replacement went smoothly for you!
Any updates?
Code hasn't returned, the fuel pump was the problem.
No one has the pump in stock. Even AutoZone is special order.
Did you say fuel pump is the problem?…my customer has the same P2635 🙌😭
Yes. Fuel pump (not the high pressure direct injection pump on the valve cover, the in-tank pump) as well as the active grille shutter assembly. I have no idea how or why those two things are tied together on the same code, but both were faulty and needed to be replaced to resolve the issue.
@@AllThingsMech I think that fixed my customers 2017 truck…I installed new fuel pump n they haven’t got in touch with me so that means everything is good 👍