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Discussion Starter #1
So...

Way back when, I was having an ABS on left-turn problem. ABS code read C0035, left front. Going off of the forum's advice, I checked my wires and harness. Turns out they were fine, and the problem lay within the hub itself.

So, I changed out my left front wheel hub, and it was fine for about a week. Then the ABS light came back on (without the ABS on left turn problem) so I plugged in my reader again, and this time it said C0040, right front.

Checked the wires, and it was fine, so I changed out the front right wheel hub. Problem went away for a good six months. It was great.

NOW IT'S BACK!

ABS cuts in randomly, left and right turns. No set pattern, really. Now my ABS light is one, and it reads C0090, right rear #1 circuit malfunction.

Does anybody have any idea why my ABS modules are going out one at a time? Or, how to fix a C0090? I really don't want to keep changing out wheel hub after wheel hub lol.
 

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I guess it's possible that your rear hub just happened to fail... the hubs on these cars are known to fail often - so it's probably just coincidence...
 

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Discussion Starter #3
That is indeed a possibility, and is probably what has happened... but man, what did I do in my previous life to have three of four wheel hubs go out within six or seven months, one at a time?! Talk about bad luck... Not to mention my oil pressure sending unit went out a couple of weeks ago... *rant*
 

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Look at the bright side - you're getting them all out of the way at once (hell, I'd be tempted to just replace *both* rear hubs at the same time). And they're all basically the same age this way. :)
 

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Are the actual hubs or bearings bad on those you replaced? Or, is there something else going on?

Have replaced the passenger side twice and the driver side once on our 2012. Have not to my knowledge had any codes pop up for them though. Dunno if the hubs are of a poor design or what the deal is, but yeah they fail. We did get 140,000 miles out of the original on our driver side and probably could have gone a few thousand miles more on it.
 

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Discussion Starter #6 (Edited)
Well, I couldn't find any issues with the wiring at that time (I'll say why I have it bolded in a bit) and I went to an actual shop to get a second opinion and they agreed that it was the hub. After changing out the hubs, the problem went away, so I was happy.

@12 lt I waited until the ABS light / TC light came on for each case, so I could figure out exactly which hub was going bad, that's how I got the codes.

Now it's back... here's the thing. Yesterday it was throwing a C0900 code, for the right rear ABS circuit. Today it's throwing a C0035 again, front left ABS circuit and no C0900. It's jumping around. I'm so confused. Could a bad wire cause the problem to jump around?
 

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Hmm, that's really strange. Not sure if there is a common wire that could throw codes for different hubs like that. Maybe a failing ABS controller? But that is assuming that there is a separate computer for ABS? Or maybe it's just part of the ECM? Not really sure.

Hopefully someone that actually knows what they are talking about chimes in, becasue I'm just guessing at this point!! ;-)
 

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Shorts or wiring issues can cause all kind of intermittent headaches. No clue if in your case the wiring is the problem or not. If you had a shop that gave a free estimate that could tell you definitively that yes the hub is bad, that would definitely be helpful. I would probably try to at least check the hub myself at the very least. I guess a question I am wondering about now is why we never had any abs/tc lights come on when ours have gone bad. I mean it was bad enough on passenger side I could feel it in the wheel in curves and I could hear it. Dunno if my wife had lights come on and did not tell me, she usually is pretty good about telling me when any cel comes on. Out of curiosity now I guess I am gonna have to scan our car and see if it has any stored abs codes.

The service advisor at the dealership on our first bad hub basically told me that these cars are susceptible to pothole hits and even suggested our having a gravel drive would contribute to a hub going bad.

As to the hubs going out, how many miles and what kind of roads? It may just be that you were lucky to not have to change any before this point. All in how you chose to look at it I guess. Had replaced 3, all on the front, on our 2012 by the time we were around 140,000 miles. Have not as of yet had to replace either of the backs(knock on wood), but sure the time is coming. My wife hit a pot hole hard enough to bend a back rim back around 85,000 miles, but to my knowledge as of yet that hub has not given any issues, close to if not a little over 150,000 miles on the car now.
 

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Discussion Starter #9
@12 lt

It's an 08, 111k or so. Roads aren't bad, mostly city / highway driving, very few rural roads or gravel.

Here's my theory on why there are no codes or ABS/TC lights. It happened to me too, where there would be no codes stored in the system while my car was doing the ABS-on-turn thing. I could be wrong, but here's what I think. The car actually doesn't think the sensor is going crazy. The computer genuinely thinks that the car is losing traction based on the signal from the ABS system. It doesn't know that the ABS signal is actually in error, until the ABS sensor actually gives way. That's why it doesn't throw a ABS/TC light or ABS code. Or in your case, it's still receiving what it believes to be a good signal from the ABS module in your bad wheel hub, and thus didn't set an ABS code. That's my opinion, anyway.

The ABS/TC light went away on my way to work... so now I'm even more confused. I just want it fixed now :( I was gonna drive about 10 hours to VA for a wedding in a few weeks... Hopefully I'll get it sorted before then. I'm not overly keen on driving that distance without ABS or TC.
 

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Discussion Starter #10
Well, the ABS light went away for a day or so, and now it's back.

Plugged in my handy dandy ABS code reader, and it's pulling four codes now, which is a little concerning.

Current / MIL: C0035 (Left front ABS circuit)
History: U0101 (Lost communication with transmission module)
U0145 (Lost communication with body control module)
C0561 (System disabled information stored)

Please note; there were no OBDII check engine codes stored, these are all purely ABS. Could my EBCM be going out? I sincerely hope not...

Does anyone have any tips or ideas?
 

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Is the bcm a common component with all those codes? If so I would guess you either have an issue with wiring going to the bcm or the bcm itself causing it to throw these codes. As much as I hate dealing with shops, might be something to have to have a shop diagnose. I would be doing some calling around locally if it were mine, competent brake shops or try to talk with a mechanic at a dealership. Maybe pm Maven, best as I recall he is a certified gm technician.
 

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Discussion Starter #13
Is the bcm a common component with all those codes? If so I would guess you either have an issue with wiring going to the bcm or the bcm itself causing it to throw these codes. As much as I hate dealing with shops, might be something to have to have a shop diagnose. I would be doing some calling around locally if it were mine, competent brake shops or try to talk with a mechanic at a dealership. Maybe pm Maven, best as I recall he is a certified gm technician.
Yeah, I agree. My girlfriend's father was a GM tech with his own shop, and he's been trying to help me out. But he lives a couple hours away, and it's hard to go back and forth.

As a result, I made an appointment to have my Impala brought in to a shop on Monday... I agree that it comes to a point where more skilled hands than I have are going to be needed.

Damn if that's going to stop me from trying to solve it in the meanwhile! I'm just dreading the bill is all...
 

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Damn if that's going to stop me from trying to solve it in the meanwhile! I'm just dreading the bill is all...
Yeah, no kidding, too bad there is not a way to check these modules. Good luck, hope you are able to figure it out without taking it to a shop.
 

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My 2013 LT started warning Stabilitrak Error when I was turning hard left to park in our tight driveway. Found an ABS code C0035, right front. Only around 85K miles. Put it up with it until preparing for a 3000 mile trip, then worried it might do bad things at highway speeds. Got a mechanic to replace the hub and do the left as well and rule them out. Next day, same thing C0035. We took the trip. While en route, figured the cable had to be the problem, so ordered pigtail assembly replacements for both. Did the left first, saw no issues. Then the right, where on exposing the twisted pair I immediately saw the broken conductor inside the insulation at the place where the cable assembly was secured to the control arm. Wire tie must have been too tight so it flexed at that point with every turn. No more problems 4000 miles later. See light spot on blue wire in center of photo.
 

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Then the right, where on exposing the twisted pair I immediately saw the broken conductor inside the insulation at the place where the cable assembly was secured to the control arm. Wire tie must have been too tight so it flexed at that point with every turn.
This is frustrating. The QA guys in Detroit should have found this issue several years earlier, followed by a fix being implemented in production, such as using a wire clamp / tie down that doesn't pinch the loom so tightly.

For sure, I found this on my 07, so by 2013 I would have expected a fix to have been implemented :(
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One thing I find interesting is comparing how it's implemented on the gen8's (and gen7's) with how it's done on Luminas, which were replaced by the Impala in 2000, and also built on the w-body.

Rather than running the wiring harness across the front rail of the subframe and out along the control arm, where it sees lots of flexing, on my Lumina, the harness comes thru the shock tower, aft of the strut, fairly high up, and goes straight to the steering knuckle, and, IIRC, has a beefed up length of wire over that span. The key point is that the flexing isn't concentrated at one point, but spread over a length 12" or more, which makes for a much more durable wiring harness.

This seems to be one of those cases of the losing the recipe and having to re-invent things :(

Doug

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Yeah, I haven't had a single issue with the ABS system in my 2005 Buick LaCrosse, which is also on the w-body platform - nor have I had this the issue with ANY other GM I've owned. Like you said, for as long as the 8th gen Impala has been made - and how many they have sold, you'd think that they would have addressed this issue long ago... It really is ridiculous when you think about it. I have a feeling that it's a big money-maker for their service departments... I hate to think that the purposely leave a design defect in place in order to boost their service department sales, but....

However, that being said, these cars are still one of the best bargains out there - and it's a relitively cheap and easy fix, so I can live with it. :) The key is to fix it yourself instead of taking it to the dealership for these well-known, easy-and-cheap-to-fix issues....
 

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Discussion Starter #19
Alright, after some weekend sleuthing, I think I have narrowed the problem down to one of two issues.

BTW, the shop was unable to find any issues. Surprise, surprise.

Anyway, I think it's now either going to be my EBCM or the wiring harnesses like @jtrosky and @Silvermeteor have said. So, I've ordered two of the pigtails and will swap them out this weekend to see what happens. I hope to goodness that's the issue... This ABS problem is driving me crazy. I've never had a problem dog me for so long before and I *really* don't want it to be the EBCM.

Wish me luck, I'm going to go sacrifice a goat to the ABS / Electronics gods.
 

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Alright, after some weekend sleuthing, I think I have narrowed the problem down to one of two issues.

BTW, the shop was unable to find any issues. Surprise, surprise.

Anyway, I think it's now either going to be my EBCM or the wiring harnesses like @jtrosky and @Silvermeteor have said. So, I've ordered two of the pigtails and will swap them out this weekend to see what happens. I hope to goodness that's the issue... This ABS problem is driving me crazy. I've never had a problem dog me for so long before and I *really* don't want it to be the EBCM.

Wish me luck, I'm going to go sacrifice a goat to the ABS / Electronics gods.
Make sure you inspect thoroughly. I've seen multiple damage spots on a single harness, all from the tie downs. So don't splice in at the first break - make sure there's not another bad spot upstream of that !

If you can't ID a bad spot, then try to go back as far as you can, such as near where the wires split off from a larger harness.

I hope this fixes it for you. I know it's been perplexing.

Doug

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