339K&Counting

The RWAL and brake light have been on for some time.
I changed the fluid in the rear diff and I was surprised that the RWAL / brake light went out,. But came back on after about 50 miles. The only part of the antilock system that could possible be affected by a fluid change is the speed sensor on the rear diff??? Can I assume that the speed sensor is okay since the light went out??. Buy a new sensor or adjust the gap?? I checked the sticky and did a search, but didn't see this mentioned. I did print out the five pages of the FSM on antilock system. TYIA

jimbo486

Sounds like it's functioning intermittently. If the ABS light is on continuously, I would bet that it's just going bad and I would replace it. Adjusting the gap won't do anything as the gap is more than likely where it should be as it sits. The RWAL sensor is the one in the rear diff. and is used solely for the ABS module.

j_martin

Retrieve the fault code off the RWAL controller. Grounding the diagnostic connector on the controller will make the light blink the code.

Proper diagnostics are the fastest and least expensive path to a repair. If you have extra money, just send it to me. I can put it to good use.

patdaly

Any possibility that the fluid had enough metallic fines that effectively closed the air gap ( created continuity ) ?

If you changed the oil and didn't get the pumpkin cleaned sufficiently, it would take some time for the oil to drag enough metallic stuff to do it again, though 50 miles doesn't seem like enough.

How did the old oil look?

maybe368

Just one comment, I had years worth of trouble with my RWAL Brake system and it never once recorded a fault code. I don't know why, it just didn't...Mark

339K&Counting

Thanks for answers
I will pull the code; I was just being lazy hoping the problem was the sensor. When the weather improves - below zero right now.
Jimbo - maybe just the wording. you said sensor in the diff? I checked my pages and I only see the speed sensor mounted external to diff. I don't see anything in the diff. Did I miss something??
The oil in the diff was ugly brown. the seals on both axles were shot- I replaced them. I have 11 miles of dust / dirt / gravel to get to town, so round trip is 22 miles. I think that the dirt was going past the seals into the diff?? Also diff fluid was leaking out of the seals.
Thanks

jimbo486

My apologies. By diff., I meant rear end. Not the carrier but I understand the confusion. The speed sensor you mention is mounted externally near the top of the housing and is for the RWAL/ABS module.

Hunted and pecked from a Galaxy S4.