2004 QC 4x4 SLT Hemi
with rear abs only option.

Using an Actron 9280A scanner. Started out with a #37 code (rear sensor erratic).
Replaced the diff sensor (Dorman 970-024 ABS Sensor) , no joy. :-(
ABS and brake light turns on and "bings" after a mile or two of driving.

Ignored it for a few months, switched PCMs to fix an emissions problem.

Now abs light comes on immediately and flashes. Ready to attack this abs issue again, now I see 3 codes abs related:

#37 rear sensor erratic
#82 tone ring teeth factor out of range
#83 tire revolutions per minute factor out of range

Today I pulled both battery cables. Took C216 connector apart, tested the #1 and #2 pin (dg wires for rear sensor) and got 1.9Mohm. Seems ok. Took connector off abs unit, cleaned it with compressed air, applied some dielectric grease. Replaced all connectors, connected battery.... no joy. I pulled out the new sensor, cleaned the sensor side, and put it back in.... no joy.

What next ? I don't have a scanner handy right now, but since the abs starts flashing immediately, I think I still have problems.

Thanks!

 

All three of those codes are directing you to the rear end. Have you pulled the cover and inspected everything?

 

All three of those codes are directing you to the rear end. Have you pulled the cover and inspected everything?

 

Should have a scanner to use again in a couple days. Its time to swap oil in the rear anyway, I'll look in there later this week and see what the tone ring looks like.

Having just gone through a PCM replacement to solve an emissions issue, I'm sensitive to the fact that the problem may not be sensor or wiring related at all...

Is there a procedure to test if the abs module is good/bad?

If I replace that module with a junkyard used one, does it require the dealer to program it?

thanks!

 

i would double check the wiring harness thag runs from the diff up to the frame, in my 07 i was getting all kinda of crazy abs/tsc codes and track control would kick while doing 80kph down the road, i found the smallest nick in the wire (after pulling the looms and everything off) and there was a little bit of green, gave the wire a tug and it broke, repaired the wire and no issues since

connor

 

Used the scanner to erase the ABS codes. On next key cycle, 37 is gone... but 82 and 83 persist. Doesn't make sense, the signal related to those codes would require moving the truck - but all I did was cycle the key.

Wondering if the Dealer flashed my replacement pcm for 4wheel abs, rather than rear wheel abs.

Onward... pulled the diff cover... found the tone ring came into contact with a piece of the lsd bearing shell. tone ring looked ok, except one tooth is half broken off. Guess its enough to cause the 37 code.

I put it back together... 1 mile down the road, 37 is back.

Can I swap out that tone ring w/o messing with the bearing setup for the ring alignment? Wondering if pulling the axles and bearing caps will allow the diff to slip out of the housing...

 

what caused the contact? something had to move that shouldn't

 

Its the dreaded steel bushing shells (some call them clips) in the Limited Slip diffs. Pretty much an epidemic on these 9 1/4 rears.

Back to my question... what needs to happen to swap out the tone ring?