Cummins Diesel Forum banner

ABS Module-what ive learned.

9.5K views 3 replies 2 participants last post by  5.9fan  
#1 ·
This is a not so brief write up of my adventure dealing with the 4 wheel ABS system on my 01. I hope it saves people in the same boat as me some time/ money/ or aggravation.

Back in June, The ABS and BRAKE lights came on in my truck, along with a complete lack of ABS system function, which had been working well up until that point. The truck still stopped well under normal conditions, however any hard application of the brakes, or with any loose material on the road, the rear brakes would lock up and the truck would skid badly. By coincidence, one of my original brake lines failed a week later, so I elected to change them all (they were all junk) as well as the ABS module.

The lines were difficult, as the abs block has a number of different fitting sizes and flares, some of which are not available aftermarket, or without excessive effort. I ended up purchasing some from a dealership, and making some conversion lines with aftermarket parts. I elected to change out only the mechanical portion of the ABS unit, as the big pro model scan tool at work indicated ABS pump motor problems.

Replacement of everything went smoothly, but the lights remained on, and the ABS still did not function. I drove the truck carefully for the remainder of the summer, as ABS parts are quite expensive.

With the onset of winter I was ready to change the ABS computer, which I did. Bear in mind that this unit was purchased from a reputable dealership and ordered with my VIN. Upon installation, the ABS system began to function, however its action was delayed, and the ABS light was blinking (looked like 'blink codes').

Another round with the scan tool indicated no motor codes, but instead a host of rear axle speed sensor, and rear axle dump solenoid codes. Testing with the scan tool indicated that both were working fine. In desperation, I began searching through the menus offered on the tool until I found one named "Pinion Preferences". Under Pinion preferences, it indicated that a Chrysler Corporate 9.25 axle was selected.:shock: Since it offered further options I selected continue and was asked if I would like to change the axle to the only other option, a DANA (size un-specified). With the change made, ABS function has improved, and the lights have not returned.

I called the dealer who checked his computers and found no mention of programming after installation, or of any reason why it would be set up for a 9.25. He re-ran all part numbers and everything came up correct. NONE of the codes showed up on a standard scan tool, all were only accessible VIA the pro model unit.

Both units were in the neighborhood of $500 apiece.:buttkick:

Scan tool was a SNAP-ON Solus.
 
#2 ·
Thank you for a most informative post!
I'm having a similar problem.
 
#3 ·
Hope ya get it all fixed up, Clunk!

I forgot to mention that my system bled out just fine after replacing all the hydraulics. I was not sure weather or not the ABS module would bleed out without being cycled by computer, but it did fine. The SNAP-ON scan tool does list bleeding capability, but I did not need it. I started in the far corner (passenger side rear and worked my way closer to the master cylinder.
 
#4 ·
ALSO: When I called the dealer back, he told me he would make a note of my problem and solution in the computer system. He said that note would be visible to other dealers, so that they could inform customers of the issue. Weather he did that, or weather anyone will see it I don't know, but it should be there...