This is a rather long post, but it has lots of info because I have been troubleshooting for a while and am just lost now.
I have a 2001 4.0l Aurora with 193k miles, I bought it with 118k 7 years ago. For the past two months, the ABS and Trac Off light would sporadically turn on and off with no discernible pattern. About a week ago the ABS and Trac Off light came on, and have stayed on everytime I have turned the car on. At the same time,
Okay my situation is just a little different. I have a 3.5 rather than the 4.0, 2001.
My 'Trac Off' light has been on continuously since I bought the car a few years ago. The owner at that time said it was nothing to worry about, his mechanic had not been able to get it to go off and stay off. Didn't seem to affect the car.
Unlike the original poster of this subject thread, my ABS light does NOT come on and stay on.
A local mechanic, that seems real knowledgeable, read my codes and attempted to re-bleed my brakes just recently. But something keep resetting a code that would not allow him to bleed the brakes. He told me I needed to get a new or used EBCM (electronic brake control module) as the ABS system was keeping him from being able to bleed the brakes thoroughly. (Sorry I have forgotten the exact code number that he mentioned, I have a phone call in to him to ask for that code #).
Help please, I made this posting a while back and included a link to a 'pdf document'. I had saved that pdf document on my computer, but when I went to open it I could not? Seems as though it is a 'files' format,...whatever that is?
My saved document says it is a Adobe Acrobat Document, but it has a 'lock symbol' by the icon? And it says files. How do I go about opening it?
Don't go spending money on a EBCM yet... Fix your steering sensor and then see if you still get codes for the EBCM.
I repaired mine. It was a cold solder joint inside the EBCM unit.
The EBCM unbolts from the brake solenoid body. You can open the unit with a little bit of effort and re-heat all of the large solder joints.
That repaired module is on my 2002 Aurora parts car, after the car got rear-ended in November. It worked fine when I reinstalled it, and it works now.
It's an easy fix, just time consuming to remove the module and separate the halves.
I've just removed my EBCM to see if I could find that cold solder joint(s) they say exist in quite a few car models. Taking the EBCM apart is not exactly an easy job as it is VERY THOROUGHLY bound together with what appears to be a LOT of silicone sealant?
Anyway I got it apart, and I've looked at the solder joints I can see readily on the upper portions on the circuit board. I can NOT see any bad joints??
Sure I might resolder all of them, but that does not tell me I got the problem fixed? And I assume I would have to reinstall it and then test it to find out that answer. Then if its not fixed I have to take it all apart again,...doesn't sound too appealing.
The pump motor your codes refer to is part of the anti-lock brake and traction control unit located at the bottom LF corner of the engine cradle. You can't miss it; all the brake plumbing on the vehicle passes through this module.
And that pump motor has a chassis ground wire that exits the motor case and is bolted to an adjacent chassis hole. That chassis connection can rust/oxidize. Remove the bolt and apply a dose of wire brush and use star washers on both sides of the terminal when reassembling.
A broken chassis ground wire would also be a possibilty.
So a bad ground wire on the ABS control module could be a possibility,...or give a bad code for that module?
I just found this bolt missing on what appears to be some sort of grounding 'plate'? Just in case I found a proper threaded bolt and tightened it in.
I subsequently 'washed' that EBCM board off with some electronic cleaning fluid, and took a closer look at it. I believe I may have found a few suspect solder joints. Tried taking some close up photos,...any comments?
Does anyone know of a reliable outfit that repairs these boards?? (I once had a Xerox monitor that had those bad capacitors from China, and an outfit set itself up to repair those circuit boards by mail order)
So I sent my EBCM unit to these folks and they returned it quite promptly. I then took the vehicle and the repaired EBCM unit to a very knowledgeable mechanic here in St Augustine to have him reinstall bit, and check out all the codes, etc. He called me up several days later to inform me that the unit was not working.
We agreed that I should return the unit to those repair people who would warrant their repair. Additionally he supplied me with a circuit diagram of what he figured the problem was:
the EBCM missing 12 volt signal to PCM on C2-2 circuit 464. All power & ground to EBCM good
I enclosed this 'diagnoses' with my EBCM and returned to My Air Bags. A few days later I had a phone call from them asking me why I had sent the unit back,...it supposedly checked out OK to them?? I told them I had enclosed the 'diagnosis diagram' given to me by my master certified mechanic. The lady on the phone seemed unaware that there was such a paper in the returned box.
Several days later I got the EBCM back in the mail, with no explanation as to what might have been wrong? I also noticed that the extra silicone sealant I had put onto the unit's edges before reinstalling the EBCM after it was returned the first time, did NOT appear to have been disturbed? I thought, had they really reopened the unit I had returned to them, or did they just run some sort of external check (test), then packed it up and sent it back???
At any rate when the EBCM came back the second time it was reinstalled by the mechanic, and found to NOT be working again !!
Anyone have a comment on the wiring diagram and diagnosis by the mechanic I'm using?? BTW he informed me that he grew up in the Detroit area and studied become a mechanic at the very time that all of this hi-tech electronics 'stuff' was first coming out for all of our new cars. He claims intimate knowledge of the subject.
Last Edit: Feb 4, 2016 13:01:14 GMT -6 by beiland: added image of EBCM schematic
Start out simple, 1. a bad battery can cause pcu connection problems. 2 bad abs wheel sensors cause the tracking and abs code problems. 3. Bad ABC control module, don't buy new have old one repaired is easier as it's oem to that vin. 4. Bad wheel bearings cause bad traction and abs not to function right.
Last Edit: Jan 22, 2019 7:39:38 GMT -6 by RCA1186: Charter of Conduct Violations