Front ABS Wheel Speed Sensor Replacement

[DanW]

I have an ABS light, Service 4wd light, and a couple other lights I think related to automatic braking (I have adaptive cruise).

I´m suspecting a bad wheel speed sensor on the passenger front because my TPMS sensor there has been inaccurate and occasionally does not read, causing a TPMS warning light.

Is there another potential problem I should be looking for?

It looks like the wheel speed sensor is pretty simple to replace. Any suggestions from anyone on that would be appreciated.

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[fourfa]

Wheel speed sensor is unrelated to TPMS, totally separate systems. But the speed sensor does dangle alongside the brake line, it’s possible for it to get damaged I suppose. Or pulled when articulating, especially if you have a lot more droop than stock

 

[Not2Late]

Wheel speed sensor is unrelated to TPMS, totally separate systems. But the speed sensor does dangle alongside the brake line, it’s possible for it to get damaged I suppose. Or pulled when articulating, especially if you have a lot more droop than stock

I had what I thought was a bad speed sensor on my front passenger side as well. Turned out it was the wire from the sensor to the first connector. I had managed to "stretch" it or damage it while off-roading. Trying to use my Mojave like a Rubicon...

Could not see damage under the wire wrap. Tech found it. You may try unwrapping the wire to see. A bad hub can also cause the ABS sensor to not work right. Something to do with excessive play as it wears and maybe grit from wear interfering with the magnet of the ABS sensor.

 

[DanW]

I had Autozone scan my OBD and it showed the right rear wheel speed sensor was bad. So I replaced it. Lights are still on. I´m going to scan it again tomorrow and will probably buy a new Mopar part. The part I used was from O´Reilly. It fit perfectly, but the size of the end of the sensor was slighly thicker than the OEM, so maybe that´s it? I dunno.

The old one was very dirty and covered with what looked like brake metal dust. I cleaned it off. I was thinking about plugging it back in after cleaning it. I kinda wish I had done that. But I´m going to still put a new Mopar part in it.

Interestingly, I went to two Mopar sites and @AllMoparParts.com had two part numbers, both saying they would work on my Gladiator. One was $10 and the other was $26. Can anyone shed any light on that? Another Mopar site only showed the $10 one. Interesting.

 

[AllMoparParts.com]

I had Autozone scan my OBD and it showed the right rear wheel speed sensor was bad. So I replaced it. Lights are still on. I´m going to scan it again tomorrow and will probably buy a new Mopar part. The part I used was from O´Reilly. It fit perfectly, but the size of the end of the sensor was slighly thicker than the OEM, so maybe that´s it? I dunno.

The old one was very dirty and covered with what looked like brake metal dust. I cleaned it off. I was thinking about plugging it back in after cleaning it. I kinda wish I had done that. But I´m going to still put a new Mopar part in it.

Interestingly, I went to two Mopar sites and @AllMoparParts.com had two part numbers, both saying they would work on my Gladiator. One was $10 and the other was $26. Can anyone shed any light on that? Another Mopar site only showed the $10 one. Interesting.

I show only one Rear Speed sensor for your application in our dealer data, Its as follows
https://parts.allmoparparts.com/oem-parts/mopar-wheel-speed-sensor-68579091aa

Please let me know if you have any other questions at this time.

Thank you,
- Benny

 

[DanW]

I show only one Rear Speed sensor for your application in our dealer data, Its as follows
https://parts.allmoparparts.com/oem-parts/mopar-wheel-speed-sensor-68579091aa

Please let me know if you have any other questions at this time.

Thank you,
- Benny

Thanks, Benny! Is that one for the Gladiator or the Wrangler? Or are they both the same? Remember, I have both a 2018 JL and a 2021 JT.

I sent you a PM with my VIN, to be sure.

 

[AllMoparParts.com]

Thanks, Benny! Is that one for the Gladiator or the Wrangler? Or are they both the same? Remember, I have both a 2018 JL and a 2021 JT.

I sent you a PM with my VIN, to be sure.

Gladiator but feel free to send the VIN and I will double check it

- Benny

 

[DanW]

Update....So the scanner said right rear wheel speed sensor, so I replaced it. ABS/Svc 4wd lights still on. I cleared the codes and they came right back without turning a wheel. I then replaced the replacement. No change, so I took the first replacement and replaced the left rear. Still no change.

So what does the hive think? ABS sensor? DTCM/TCCM?

Anyone know how much it costs to get a new ABS sensor?

I´m at a loss on this one and may throw in the towel and take it to the Jeep dealer.

I did put it into 4 low and it seems to engage the 4wd...I was just curious about that.

 

[DylanM]

So you're getting a fault code for the right rear wheel speed sensor... what's the actual fault code?

You need to consider that fault codes indicate there is a problem with a system or circuit, they don't necessarily mean a specific part is bad (although that is one possibility). Replacing the right rear speed sensor didn't fix the issue because something else in that circuit is causing the fault. Troubleshooting is required to figure out what the actual cause is.

 

[DanW]

So you're getting a fault code for the right rear wheel speed sensor... what's the actual fault code?

You need to consider that fault codes indicate there is a problem with a system or circuit, they don't necessarily mean a specific part is bad (although that is one possibility). Replacing the right rear speed sensor didn't fix the issue because something else in that circuit is causing the fault. Troubleshooting is required to figure out what the actual cause is.

The code is C003A-1D.

I´m wondering if before taking it in I should pull the rotor and see if I can inspect the tone ring for debris/metal? Maybe I can spray some contact cleaner on it and in the hole for the sensor?

 

[DylanM]

The code is C003A-1D.

I´m wondering if before taking it in I should pull the rotor and see if I can inspect the tone ring for debris/metal? Maybe I can spray some contact cleaner on it and in the hole for the sensor?

If the code immediately kicks back out after being cleared and the wheel hasn't even rotated yet, then it's unlikely debris on the tone ring would be the cause.

C003A-1D indicates the right rear wheel speed sensor circuit current is out of range, ie, when switched on the ABS module expects to see a signal from the sensor within a certain voltage range but is instead seeing voltage either above or below that. Causes include the sensor itself which you've already replaced, damaged/dirty/loose terminals in the wire harness connector, a short to ground on either of the two sensor wires, a short to voltage on either of the two sensor wires, an open (break) in either sensor wire, a short between the two sensor wires, or a faulty ABS module.

To properly troubleshoot the issue you'll need to use a multimeter to check the sensor wiring for any of the listed issues.

 

[DanW]

If the code immediately kicks back out after being cleared and the wheel hasn't even rotated yet, then it's unlikely debris on the tone ring would be the cause.

C003A-1D indicates the right rear wheel speed sensor circuit current is out of range, ie, when switched on the ABS module expects to see a signal from the sensor within a certain voltage range but is instead seeing voltage either above or below that. Causes include the sensor itself which you've already replaced, damaged/dirty/loose terminals in the wire harness connector, a short to ground on either of the two sensor wires, a short to voltage on either of the two sensor wires, an open (break) in either sensor wire, a short between the two sensor wires, or a faulty ABS module.

To properly troubleshoot the issue you'll need to use a multimeter to check the sensor wiring for any of the listed issues.

That makes perfect sense because it is immediately triggering the warning lights when I clear the code. So either an issue somewhere along the wiring or the ABS module.

If I had to guess I´d bet the module is the culprit. The parts of the wiring I can visually inspect look perfect. I have not looked at the wiring under the hood near the ABS module yet, though. That will be next.

Unless I find something there, a trip to the dealership is the next step.

The help from you and Benny @AllMoparParts.com is much appreciated. He also included a chafed or damaged wire as a possibility.

 

[DanW]

Update...Took it to an Indy shop. I was hoping it´d be cheaper than the dealer, and it was...a little. $169 for diagnosis vs. $200 at the dealer. Ok. it´ll get me a fill up.

The good news: It was not the ABS module. It was two chaffed wires. The tech did a good job of finding it.

The bad news. It took him some time to find it.

The worst news. A new wiring harness, going from under the hood to the rear, is $3000 parts and labor. Yuck.

The better news....They are going to just fix/splice the wires and do it in a way that should not fail again. The tech is a Jeep guy who wheels his Jeep, says he knows what he´d doing and will do an exceptional job.

The bad news. $800. With the diagnostic fee and tax, it´ll be just over a grand.

The best news. Jeep will be fixed and back to 100% good health! I get it back Monday.

I appreciate the help and suggestions here. You guys are THE BEST!

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