C1236

DTC C1236

Circuit Description
The electronic brake control module (EBCM) monitors the voltage level available for system operation. A low voltage condition prevents the system from operating properly.

DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC C1236 System Supply Voltage Low

Conditions for Running the DTC
^ The vehicle speed is greater than 8 km/h (5 mph).
^ The ignition voltage is less than 10.8 volts.
^ The system relay is commanded ON.

Conditions for Setting the DTC
One of the following conditions exists for 0.72 seconds:
^ During initialization or when the system is inactive, the system voltage is less than 10.8 volts.
^ During the system operation, the system voltage is less than 9.36 volts.

Action Taken When the DTC Sets
If equipped, the following actions occur:
^ The EBCM disables the Antilock Brake System (ABS)/Traction Control System (TCS) until the DTC becomes a history DTC.
^ The ABS indicator turns ON.
^ The Traction Off indicator turns ON.
^ The message center displays the Service Traction System message.

Conditions for Clearing the DTC
^ The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
^ The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

Diagnostic Aids
^ Test the charging system. Refer to Diagnostic System Check - Vehicle. Diagnostic System Check - Vehicle
^ Possible causes of this DTC are the following conditions:
^ A charging system malfunction
^ An excessive battery draw
^ A weak battery
^ A faulty system ground

Test Description





The numbers below refer to the step numbers on the diagnostic table.
2. Use the scan tool in order to inspect the voltage to the EBCM.
3. Use the scan tool in order to inspect the voltage to the instrument cluster. A low voltage value in multiple modules indicates a concern in the charging system.
5. This step verifies that the condition is still present.