Re: 2001 ABS problems
Do you know a mechanic that has a GM Tech 2 or other high end scan tool that can access the non-powertrain diagnostics? The simple scanners that you can get at Sears, Autoparts Stores or that most non-dealer mechanics have cannot read the codes. If you can get the codes read I can help with some diagnostic procedures. The ABS DTC codes are the following:
DTC C1242 or C1243
DTC C1255 or C1256
The ABS system is not part of the base brake system but basically rides on top of the base brakes. If you have an intermittent I would suspect the problem is electrical and not associated with the wheel speed sensors although they cannot be ruled out. The first thing to do is to check the voltage and grounds at the EBCM and BPMV to make sure there are no corroded/loose connector pins or ground locations. You should also check the connectors and wiring from the wheel speed sensors to the EBCM.
When a DTC code is present the ABS shuts itself off. Since the problem seems to be intermittent probably the rumble you are hearing is the ABS system doing its self check each time the intermittent problem goes away.
Last edited by BillD64; 01-06-2010 at 02:43 PM.