DTC C0235, DTC C0236, DTC C0237: Rear Speed Sensor Signal Circuit Open

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2001 GMC Savana Special, 2001 GMC Savana Camper Special, 2001 GMC Savana, 2001 Chevrolet Chevy Express, and 2000 GMC Savana Special. However, it is still accessible from the selected car via links, so may be relevant.

Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK under DIAGNOSIS & TESTING. After performing diagnostic system check, go to next step.
Using scan tool, clear DTC(s). Operate vehicle at speeds greater than 12 MPH with brakes released or 20 MPH with brakes applied. Recheck DTCs. If DTC resets, go to next step. If DTC does not reset, problem is intermittent.
Raise and support vehicle. Turn ignition off. Disconnect EBCM harness connector. Set DVOM on DC voltage scale. Connect DVOM between chassis ground and vehicle speed signal circuit at EBCM harness connector. Place transmission in Neutral. Turn ignition on. Manually spin wheels as fast as possible. Ensure driveshaft is rotating. Observe DVOM. If voltage reading is 5-7 volts, go to step 5 . If voltage reading is not 5-7 volts, go to next step.
Check vehicle speed signal circuit for short to voltage. Repair as necessary. After repairs, go to step 9 . If circuit is okay, go to step 7 .
Check for poor connections at EBCM harness connector. Repair as necessary. After repairs, go to step 9 . If connections are okay, go to next step.
Replace EBCM and perform tire size calibration procedure using scan tool. After replacing EBCM, go to step 9 .
Check for poor connections at PCM/VCM harness connector. Repair as necessary After repairs, go to step 9 . If connections are okay, go to next step.
Replace PCM/VCM. After replacing module, go to next step.
Turn ignition on. Using scan tool, recheck DTCs. If DTC resets, go to step 2 . If DTC does not reset, system is okay.