C1237

DTC C1237 High System Supply Voltage:

CIRCUIT DESCRIPTION
This Diagnostic Trouble Code (DTC) is designed to detect high vehicle voltage levels. This DTC is designed to protect the ABS system from high voltage damage.

CONDITIONS FOR SETTING THE DTC
This DTC will set when the following conditions are met:
^ The Electronic Brake Control Module (EBCM) has detected 17 volts or greater.
^ This DTC can only be set if the vehicle's speed is greater than 5 km/h (3 mph).

ACTION TAKEN WHEN THE DTC SETS
A malfunction DTC is stored, ABS is disabled, and the amber ABS indicator lamp is turned ON.

CONDITIONS FOR CLEARING THE DTC
^ Conditions for the malfunction are no longer present and the Tech 2 scan tool Clear DTC Information function is used.
^ One hundred drive cycles have passed with no malfunctions detected.

DIAGNOSTIC AIDS
Check if the vehicle's charging system is not working properly. The frequency of the malfunction can be checked by using the Enhanced Diagnostic function of the Tech 2 scan tool, as described in Enhanced Diagnostics.

EBCM/ABS Relay Schematic:

TEST DESCRIPTION
The numbers below refer to step numbers on the diagnostic table.
[2] Checks for voltage reading at EBCM by using Tech 2 scan tool.
[3] Checks for charging system overcharging.
[4] Checks if this DTC resets after two drive cycles.