2002 Chevy Monte Carlo ABS/Traction Control off

When checking power and ground. don’t use a led test light or multimeter, Use jumping wire you can make yourself and an old headlamp beam. You will create a decent load that will be a pass/fail. If you do it that way you will be sure of your call as testing with open circuitry is a total way to misdiagnose. a LED tester will give you a false reading as it use minimum current. If you wire hold on only 1 string, both of the tool I tell you to avoid using could and will light up or give you 12v.

Follow those instruction as its pretty simple everything is internal and those module are junk.

1. Disconnect the Electronic Brake Control Module (EBCM). Verify the EBCM powers and grounds are good.

2. Check for corrosion or a bad connection between the EBCM and the Brake Pressure Modulator Valve (BPMV).

3. If all OK, replace the EBCM.

You can use a scanner and test the pump itself when the fault is present to confirm prior to tear down

Had a similar intermittent ABS/TRAC problem in my 2001 Pontiac GP SE 3.1. Eventually the light would come on even while parked, simply by cranking the steering wheel hard over to the right. Prior to that, was noticing that the light would stay off after reset as long as I was not making right turns. Deduced that the problem was likely due to intermittent loss of circuit continuity to one of the front wheel speed sensors (WSS). Examined the wiring to the right wheel for damage, found none, cleaned and unplugged and replugged the connector a number of times with DeOxit (best electrical/electronic contact cleaner going)to wipe off any connector oxidation, and problem solved. Got lucky, tried the fix on the right front first, because that wheel had had its wheel bearings replaced a few months earlier, didn’t even have to check the left side.

Apparently the change in tension on the connector affected by moving the wheel in turns was all was that was needed to cause a momentary loss of output from the WSS, which then tripped the system off. Never tried to shoot codes, but likely would have located it easily to the right front WSS circuit. Note that I said WSS CIRCUIT, not just the VSS itself. I am an electrical engineer, and in over 50 years of professional work troubleshooting all sorts of stuff, troubleshooting electrical problems with my vehicles, and ham radio, the problem in a vast majority of the cases turns out to be with bad wiring, NOT bad sensors or components, especially in stuff that works in a harsh vibration environment like a vehicle.

The fact that your problem is tripped by hitting a bump makes it highly probable you have an intermittent connection somewhere. A failed component would likely stay failed, and you would not be able to reset the system and have it operate normally for a while until the next bump tripped it off. If you know what code is thrown, concentrate on the wiring for that component’s circuit.

I don’t know if this is true for the GM ABS/TRAC systems, but if you get to the point that you think that the main control module is suspect, there are guys who will repair yours on an exchange basis for very reasonable prices. Volvo and other Euro car ABS systems often have intermittent loss of ABS problems due to bad solder joints on the main module circuit cards, that can be easily fixed if you are handy with a soldering iron, or you can get it fixed by one of the aforementioned repair guys. Google around, there are more than a few out there.

Chris, Stonington CT.