Car model and year: 2000 C5 Corvette
A small problem with the traction control but the ABS is working fine every time.
while I accelerate quickly to the limit where traction control should activate and prevent the tires slipping, instead the ABS and TCS failure lights come on and the car throws the C1243 code. I can get rid of the lights by switching the the power off and on again. But every time I accelerate “too hard”, specially on a wet road of course, the failure occurs again. However, the acceleration is the only way to have the failure, otherwise the system seems to work fine. There’s no other codes related to ABS or TCS.
Analysis and how to do:
C-1243. Brake Pressure Modulator Valve (Pump Motor Stalled). When the car requires EBTCM intervention to correct for loss of traction or loss of handling, it either vents brake pressure off the caliper or adds (applies) pressure to caliper to increase braking. It does this in a modulated manner. It uses electronic solenoids to modulate the line pressure to that caliper: (VENT or PRESSURE)
To add pressure to the braking system a MOTOR /Pump runs. That motor is not running STALLED because its most likely junked up and need to be exercised or replaced..
You can exercise it to free it up. There are several ways to do that.. One is with the GM TECH2 or you can manually connect 12 VDC to the motor and run it.
I drive my car hard enough to keep the motor free and working. If you never use the car to its extremes, the motor can stall and throw that DTC.
***There are also the same user feedback: I had the same problem years ago. I use a clone Tech II and “exercise” my pump motor for 5 iterations every 3 months. I have not had an issue since.
I received my Tech II last week and ran the ABS pump motor five or six times. Today I took the car for test drive and yes, the warning lights stayed off! I don’t want to get too excited yet but so far it really looks like the exercising did to the trick.
More suggestions and reviews on GM TECH2 CLONE:
Vxdiag Nano GM is another alternative. I did this a few times until I purchased my Tech II which is much safer. Be careful if you try this.
Another advantage of the Tech II is you will be able to do “automated brake bleed” procedures which is the GM procedure for bleeding your brakes.
I have one and can communicate and diagnose my C6 cars.
Image 1: CANDI Module
I think all the clone Tech II are very similar however I bought this one based on recommendations on https://dwz.cn/ABPi8zl0:
Image 2: Best GM TECH2 full package