Tire Pressure System Fault

[JoeR]

So you set the car in 'learn mode' and starting with front left, let air out until the horn honks?

Exactly.

[JoeR]

That particular tool doesn't give any feedback. It transmits only.

Good to know. Thx.

[CrashTestDummy]

So you set the car in 'learn mode' and starting with front left, let air out until the horn honks?

Exactly.

Thanks. And I guess it doesn't matter where I start, the car will 'think' I'm starting at front left no matter which tire I'm deflating? Asking, because if the front left does nothing, then I'm hoping I can move to the front right to see if anything happens, and so on.

[Mooseman]

So you set the car in 'learn mode' and starting with front left, let air out until the horn honks?

Exactly.

Thanks. And I guess it doesn't matter where I start, the car will 'think' I'm starting at front left no matter which tire I'm deflating? Asking, because if the front left does nothing, then I'm hoping I can move to the front right to see if anything happens, and so on.

Yes. If one won't register, you won't be able to complete the relearn but you'll know which one is dead.

[CrashTestDummy]

Haven't gotten back to this yet. We've either had rain coming in sideways, or mid-30-degree F temps with 20 MPH winds that I'm NOT getting out in.

Had a Dr's appt today, and about 2 miles into the trip the dash lit up! Besides the pressure system fault, I got two new ones; Stabilitrack Fault and ABS Fault. Does anyone know if those are possibly related to the TPMS fault? The faults went out when I got into the car for the drive home, but each time after starting up from a stop, I could feel the ABS pulse once. I had a couple of errands to do on the way home, and the ABS pulsed after each restart, but never after that.


WTF?!?

[Sanford]

The ABS is unrelated to the TPMS issue. Probably have a speed sensor getting wacky. I believe I have had a speed sensor failure on about ever car in the fleet. Hopefully it is the rears instead of a front that requires a hub assembly replacement. I have gotten to I ignore the intermittent ABS light and wait until it stays on. Hook up a scanner that will read ABS codes and see which one is causing the problem. Supposed to be decent weather this week end, but next looks pretty crappy.

[CrashTestDummy]

Thanks. Yes, I've already replaced one speed sensor on the left rear corner. It had a ball of rust in the hole the sensor resided in, so the sensor itself might have been okay, but I was already there, and already had a new sensor, so swapped it out.

Decent weather, but COLD!! And windy!! Yes, next weekend is going to be worse.

[CrashTestDummy]

Still slacking on deeper dive on this. Been working on the bus to get it ready for a short trip in March. Discovered the radiator on the generator seeping some, so yanked it to take it to a shop for repairs. Scope creep because of 'while I'm there'....

Still posting the ABS and Stabilitrack alerts for the first drive out of the garage. Then, about 1/2 way through the second start for the trip, the lights go out and things seem normal. Still have the Tire Fault, but been busy with other things. Will probably break out the plastic wrench and have Chevy look at/fix it. Dunno, yet.

[jomama]

Had the same two issues as you. Now they’re fixed.

For the TPMS, I didn’t want to spend the $$ on the relearn tool, so I attempted the manual re-learn procedure to figure out which sensor was the fault…which turned out to be kinda pointless because when I got to the RF tire, the test couldn’t complete because that sensor failed (no way to move onto the next tire). Good data, but I would’ve had to swap tires around to complete testing. I should’ve bought the tool. Anyways, I decided to put on new tires and had all four sensors replaced at that time. It cleared the problem. I think it’s kinda silly that a single TPMS sensor failure wipes out all four on the DIC. Literally EVERY other vehicle I’ve owned with TPMS display just “—“ the bad one. So that was new.

For the ABS, I also had the same symptoms. I learned then that the ABS module was Tech 2 based and wouldn’t communicate with the newer Global diagnostic software, and finding a place with that antiquated tech (or a compatible go-between) was pretty hard (even the local dealer couldn’t/wouldn’t help). However, I eventually got the ABS code and it was indeed a bad ABS sensor (RR). I foolishly decided to buy a generic sensor from the local big chain auto parts store to replace it with. The fault remained (the sensor was bad out of the box…post-tested as an OPEN). Bought the GM OEM spec and put it in. The fault REMAINED.

So I went back to the dealer that read it for me. Was told the OPPOSITE side sensor was now faulty (coincidence maybe…I like to think the fault stack can’t see two or more or bad sensors at the same time, in lieu of thinking they just flubbed it up and wrote the wrong side on the work order). Replaced the LR (left-rear) and the fault cleared. No more problems since. Hope it helps.

[CrashTestDummy]

Had the same two issues as you. Now they’re fixed.

For the TPMS, I didn’t want to spend the $$ on the relearn tool, so I attempted the manual re-learn procedure to figure out which sensor was the fault…which turned out to be kinda pointless because when I got to the RF tire, the test couldn’t complete because that sensor failed (no way to move onto the next tire). Good data, but I would’ve had to swap tires around to complete testing. I should’ve bought the tool. Anyways, I decided to put on new tires and had all four sensors replaced at that time. It cleared the problem. I think it’s kinda silly that a single TPMS sensor failure wipes out all four on the DIC. Literally EVERY other vehicle I’ve owned with TPMS display just “—“ the bad one. So that was new.

For the ABS, I also had the same symptoms. I learned then that the ABS module was Tech 2 based and wouldn’t communicate with the newer Global diagnostic software, and finding a place with that antiquated tech (or a compatible go-between) was pretty hard (even the local dealer couldn’t/wouldn’t help). However, I eventually got the ABS code and it was indeed a bad ABS sensor (RR). I foolishly decided to buy a generic sensor from the local big chain auto parts store to replace it with. The fault remained (the sensor was bad out of the box…post-tested as an OPEN). Bought the GM OEM spec and put it in. The fault REMAINED.

So I went back to the dealer that read it for me. Was told the OPPOSITE side sensor was now faulty (coincidence maybe…I like to think the fault stack can’t see two or more or bad sensors at the same time, in lieu of thinking they just flubbed it up and wrote the wrong side on the work order). Replaced the LR (left-rear) and the fault cleared. No more problems since. Hope it helps.

Yeah, but did you actually see 'ABS Fault' on the DIC? I don't remember seeing the term 'Fault' the last time a wheel sensor failed on this car (LR sensor), but I've possibly slept since then. I took pictures of the three DIC screens on our car to post here for posterity's sake.

I actually got some time to look around the car today. Pulled the wheels and inspected the sensor connectors and wiring. I found no foul play on any of the harnesses, although a continuity test of the harness yielded continuity through the harness for the RR sensor, but none of the others. The testing process was kind of sketchy, with me jamming bits of wire into the harness connector, and flailing about with the probes on the VO meter, so the 'test' may mean nothing. If the results were true, that means either something is wrong with the RR sensor harness, or something is wrong with all BUT the RR sensor harness. I don't know.

Failing all the visuals and V-O tests, I hooked up my OBD reader again, and THIS time, got a notification that the RR sensor is failed. I'll order another sensor and see if that fixes the issue. Otherwise, it's off to the dealer for diagnostics.

ABS Fault.JPG (90.65 KiB) Viewed 71 times

Stabilitrack fault.JPG (105.87 KiB) Viewed 71 times

TPS sensor fault.JPG (107.21 KiB) Viewed 71 times

BTW, funny thing, In a past career, I worked for a guy who's name was Joe, and we all called him 'Jomama'!