Tire Pressure System Fault

[Sanford]

I just replaced a rear one. The ABS fault light has been coming on for a day or two and then going away for a couple days. Hooked the scan tool and I was not getting a MPH signal from one rear sensor intermittently, so I replaced it with a cheapy from eBay. Seems like the OEM’s are only good for about 100,000 miles. I will see how the cheapy one holds up. At least they are a quick job.

[CrashTestDummy]

I just replaced a rear one. The ABS fault light has been coming on for a day or two and then going away for a couple days. Hooked the scan tool and I was not getting a MPH signal from one rear sensor intermittently, so I replaced it with a cheapy from eBay. Seems like the OEM’s are only good for about 100,000 miles. I will see how the cheapy one holds up. At least they are a quick job.

~95K miles, in my instance!

[jomama]

Yes, I had all the same indications on my DIC. After the car had finished its onboard system check at startup, it would chime and give me all three displays. I’d scroll through them until the digital speedometer came up (because that’s what I like to put it on). Thereafter, the only indications I had were the warning lights for TPMS and ESC on the cluster itself (though, if you scroll through the DIC, I think you can pull those fault graphics up again). Once I replaced the TPMS sensors and the speed sensor(s), the faults cleared and the system startup checks would pass (i.e. I could select performance mode again and have a little more fun).

Also, FWIT, I find it’s normally easier to check continuity from the plug-to-module end of a harness, as this will test the full signal path from termination to termination. You can do it individually for each path if you have extended leads for your multimeter, or you can short the ABS sensor connector and then test for continuity from the signal supply to signal termination pins in the module connector (as I think they’re both housed within it). I feel the pins are much more accessible in the module plug, so I don’t have to second guess the results. Words of caution though (if you don’t already know them):

1) Anytime you do something intrusive (even something as innocuous as disconnecting and reconnecting a multipin connector), it COULD (not will) cause additional issues, so it’s a risk vs reward thing.

2) When using your multimeter as an ohmmeter, make sure you’re connecting to the right pins/sockets. Sometimes, if there’s other components located downstream and you just so happen to put your lead on it’s pin AND there’s a completed path for current flow, then the ohmmeter MAY provide enough current to damage said component (if it’s got solid state stuff inside). Simply put, test the right ones, don’t short adjacent pins and, when able, limit the ohmmeter to the 2 kohm scale (or diode scale, if so equipped).

My actual name is Patrick. I was in the Navy and had a guy in my division who would often reference ‘Jo and Angie’ when I’d ask him questions…to which he’d quickly (and most delightfully) follow up with ‘Jo mama Angie daddy’ (while not actually answering any of my questions). I guess it just kinda stuck with me through all these years!

[CrashTestDummy]

Yeah, I didn't want to disturb the plug at the harness end, so opted to NOT do that. And yes, I know about being careful about avoiding the wrong wire end when testing things. That can be 'fun', especially when working on 110/240V circuits.

This guy was actually put in as our team lead, so was 'Joe, our mama', shortened to 'Jomama'. . It's funny when that name comes up in conversations with ex-team members, literally decades later.

[CrashTestDummy]

Good day in the shop today! Weather wasn't too bad.... yet, and I had several projects to get out of the way. While paint dried in the battery tray on our '92 B4C, I tackled the speed sensor replacement on the Caprice. Not a real big chore, other than wrestling the tire around, and persuading the sensor to actually come out of the hole it was in after the bolt was removed. Got it replaced in good time, and the car back down on all fours. The faults are still there, but I haven't started the car eleventy-billion times yet and driven it a quarter million miles yet so the monitors reset. That will come in due time, I guess.

I'm wondering if anyone knows what the plastic anchors that hold the speed sensor harness in place at the end of the LCA are called, or, better yet, have a P/N for them? I've attached pictures so you can see. Both sides are broken, and although the harnesses seem pretty secure, I'd like to replace them, if I can.

Yes, I can use zip ties, but if the factory part is still available, I'd much rather use that. If the factory part isn't available, I'll probably just forego the replacement altogether, since they're okay as-is. Thanks.

wiring anchor 1.JPG (75.77 KiB) Viewed 3585 times

wiring anchor 2.JPG (97.97 KiB) Viewed 3585 times

[CrashTestDummy]

Finally got a chance to get the car out for a quick drive to start the 'start and drive' cycles to hopefully clear the faults on the dash. It's a short loop I usually use to 'exercise' the other vehicles in the collection when I can get them out of the shop. On startup, the usual 'Stabilitrak Fault' and 'ABS Fault' messages were displayed on the DIC, and the lights were lit on the dash.

On the way back to the house, I looked down at the dash, and all that was present was the 'TPS System Fault' light and the tire warning light was on the dash. I parked the car back in the garage, turned it off, waited a minute, or so, and turned the key on. After the system check, all that showed on the DIC was the TPS Fault. I started the car, and still, just the TPS issue seems to remain. Hopefully this issue was indeed fixed with the speed sensor R&R!

Now, on to fixing the TPS issue.

Again, does anyone know if the clips posted in the post above are still available? Thanks.

[CrashTestDummy]

Got the TPMS sensors replaced by Discount Tire. That cleared the fault, and I now have pressure readings on all 4 tires. Odd, when I picked the car up, I had a 'fill LR tire with air' alert on the DIC, and when I dove deeper to see what the pressure was at (35), I was not getting a reading on the RR tire at all. I figured I'd deal with that issue later, if necessary. Once home, I aired up the tires, double-checked the wheel torque and replaced the center caps. Checking the pressure on the DIC, and all 4 tires read proper pressure. Yaay!!