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ABS light won't go away

I have a 2002 Buick Rendezvous CX (2wd no traction control). My ABS is throwing a C0040 and C0035 code. After reading some info it seems to most likely be a wiring issue. Would a wiring issue also cause brake performance issues? At times when I brake there is a slight “pulsating” feeling in the pedal accompanied by a noise like I’m on gravel (not the bad pads/rotors noise). I can also here a very fast (but faint) clicking noise when I brake at low speeds.

Thank you

Sounds like a problem with a wheel-speed sensor(s)…Pull all the wheels and inspect the sensor, its position, and its wiring connector…check the toothed rotors that the sensors depend on for a signal…On your car, it looks like the sensors are part of the wheel hub…

The DTC C0035 indicates a problem with the right wheel speed sensor.

The wheel speed sensor is part of the bearing/hub assembly.

If the bearing begins to wear out. it causes the tone ring to become misaligned with the wheel speed sensor. This can cause the ABS to activate when it shouldn’t.

The DTC C0040 indicates a problem with the right wheel speed sensor circuit. The wheel speed sensor is part of the circuit.

So I would replace the bearing/hub assembly on the right side to see if both codes go away and the ABS light turns off.


And you can’t inspect the sensor on GM vehicles of this age. As @Tester said, the sensor is an integral part of the hub. On some vehicles you can remove the sensor and clean it or replace it. That is not possible on my 2003 Silhouette and your Buick. And the wiring is an integral part of the assembly too. About all you can do is disconnect toe connector from the ABS module clean the contacts, and hope it works.

I don’t want to be a spoiler, but . . .

According to my information

C0035 is for the right front wheel speed sensor

C0040 is for the left front wheel speed sensor