Conditions for Setting the DTC
WARNING: This page is about a different car, the 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Silverado, and 2003 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
C0235
The EBCM detects low voltage on the vehicle speed signal circuit for 500 milliseconds.
C0236
The rear wheel speed signal is less than 6 km/h (4 mph) for 5 seconds, or 120 seconds in order to set multiple missing sensor signal DTCs.
C0237
The EBCM detects an erratic rear wheel speed signal for 105 milliseconds.
P0609
The PCM detects low voltage on the vehicle speed signal circuit for 45 seconds.