C0037

ABS/VSS Circuit Schematic:

CIRCUIT DESCRIPTION
The rear wheel speed signal originates from the Vehicle Speed Sensor (VSS) which is connected to the Vehicle Control Module (VCM). The Electronic Brake Control Module (EBCM) receives the rear wheel speed signal from the VCM.

CONDITIONS FOR SETTING DTC
^ Average wheel speed for all wheel speed signals is greater than 40 km/h (25 mph).
^ Average rear wheel speed is greater than 40 km/h (25 mph).
^ No output from rear wheel speed signal for 15ms.
^ Anything which suddenly prevents (intermittent) the rear wheel speed signal to drop to 0 while the vehicle is moving greater than 40 km/h (25 mph).

ACTION TAKEN WHEN THE DTC SETS
^ ANTILOCK indicator lamp is illuminated
^ ABS is disabled

NOTE: Diagnostic Trouble Code (DTC) C0037 is a condition latched DTC which indicates the above is true only as long as the condition persists.

CONDITIONS FOR CLEARING THE DTC
^ Conditions for setting the DTC are repaired and the Scan Tool clear (DTCs) function is used.

DIAGNOSTIC AIDS
This DTC can be caused by a malfunction in the VSS, a fault in CKT 696, a damaged Powertrain Control Module (PCM) or a damaged EBCM.

DTC C0037 Rear Speed Signal Erratic:

TEST DESCRIPTION
The numbers below refer to the step numbers on the chart.
[3] Checks for VCM voltage at the EBCM.
[4] Checks resistance of CKT 696.
[6] Checks for a short to ground in CKT 696.