xzeromark

Ok, my BRAKE and ABS light are on in my car. I did all the normal check's (fuses, abs sensors, yada, yada). Now I got it scanned and I get a "no communication" error with my abs module. (at this point if you are scratching your head and saying "what!?" then turn away.)

Anyone know which what sends or picks up the singnal for ABS, is it the BCM or the regular powertrain computer? And from there what can I do to try to fix this, or atleast have a great trouble shoot method to figure out if the ABS Module or computer is fired or whatever is wrong with the car?

help

gordon24chic

I have a 99 GA and I have the same problems. Also, my Trac off will not work, don't actually know if the trac works at all - not sure what that even is really. Anyway, I had my GA scanned and got the same reply - no communication with the EBCM - I was told that it may not be communicating because I have an aftermarket stereo installed - I think that is BS. So now I have no ABS and 2 very annoying lights in my face and the trac thing. All the tech and the dealership could really tell me is "Well, you don't really need ABS anyway, may be better off without it."
I was just curious when your problem started, my began as my battery was dying on me and all my warning lights were coming on on my way to buy a new battery. If anyone has any suggestions for you be sure to send it my way.

e2helper

If you have no comm with ABS Module (aka EBCM) then hopefully just an issue with Power or Ground or serial data wire and not a bad module.

There are 3 fuses for the ABS system in the underhood electrical center. Did you check them all?

Serial data (Class 2) is used for ABS module to communicate with several other modules in the vehicle (BCM, Cluster, Powertrain Module and Remote Keyless Module). If you aren't having any problems with other modules in vehicle then there still could be a problem with the serial data wire to module (open circuit)

The ABS module exchanges serial data through EBCM harness connector terminal 12 (Purple).

Connector terminal 4 (Pink) supplies the switched ignition voltage to the EBCM.

Connector terminal 13 (Orange) supplies the battery voltage to the EBCM.

Connector terminal C (Red) supplies the switched battery voltage to the EBCM.

Connector Terminal D (Black) provides the ground for the EBCM.

Diagnostic Aids
Communication with the EBCM is not possible when excessive resistance exists in the following components:

The ground
The power supply circuits
If communication with the EBCM is not possible, perform the following actions:

Verify that the EBCM ground connection is good.
Verify that no excessive resistance exists in any of the power supply circuits.

MurphysLaw

e2helper - Can you email me at toddking@hotmail.com? I am interested in finding out more on this same issue. Along with a sporatic clicking noise coming from the hazard switch behind the dash.