C1237

High System Supply Voltage:

CIRCUIT DESCRIPTION
DTC C1237 detects high vehicle voltage levels prior to any required motor movement (initialization or ABS). Damage to the system may occur if excessive voltage exists.

CONDITIONS FOR RUNNING THE DTC
The vehicle speed is greater than 8 km/h (5 mph).

CONDITIONS FOR SETTING THE DTC
A malfunction exists if the switched battery voltage is greater than 17 volts.

ACTION TAKEN WHEN THE DTC SETS
^ ABS is disabled.
^ The ABS warning indicator turns ON.

CONDITIONS FOR CLEARING THE DTC
^ The condition responsible for setting the DTC no longer exists and the Scan Tool Clear DTCs function is used.
^ 100 drive cycles pass with no DTCs detected. A drive cycle consists of starting the vehicle, driving the vehicle over 16 km/h (10 mph), stopping and then turning the ignition OFF.

DIAGNOSTIC AIDS
Use the enhanced diagnostic function of the Scan Tool in order to measure the frequency of the malfunction.

Ensure the vehicle's charging system is working properly.

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
2. This step uses the scan tool to check the battery positive voltage circuit to the EBCM.
3. This step checks the battery positive voltage supply circuit.