C1236

CIRCUIT DESCRIPTION
This circuit is used to monitor the voltage level available to the Electronic Brake and Traction Control Module (EBTCM). If the voltage drops below 10.5 volts, full performance of the ABS/TCS/Stabilitrak is not guaranteed. During ABS/TCS/Stabilitrak operation, several current requirements will cause a drop in battery voltage. Prior to ABS/TCS/Stabilitrak operation, the circuit monitors voltage in order to indicate a good charging system condition. The circuit also monitors the voltage during ABS/TCS/Stabiltrak operation, when the voltage may drop significantly

CONDITIONS FOR SETTING THE DTC
All of the following conditions occur:
^ The vehicle speed is greater than 8 Km/h (5 mph).
^ The battery positive voltage (B+) is less than 10.5 volts.
^ The ignition voltage is less than 10.5 volts.

ACTION TAKEN WHEN THE DTC SETS
^ A malfunction Diagnostic Trouble Code (DTC) is stored.
^ The ABS/TCS/Stabilitrak is disabled.
^ The ABS indicator is turned ON.
^ The TRACTION CONTROL indicator is turned ON.
^ The DIC displays the SERVICE STABILITY SYS message.

CONDITIONS FOR CLEARING THE DTC
^ The condition for DTC is no longer present and you used scan tool Clear DTCs function.
^ The condition for DTC is no longer present and you used the On-Board Clear DTCs function.
^ The EBTCM does not detect the DTC in 50 drive cycles.

DIAGNOSTIC AIDS
^ It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
^ An intermittent malfunction can be caused by poor connections, broken insulation, or a wire that is broke inside the insulation.
^ If an intermittent malfunction exists refer to Intermittents and Poor Connections Diagnosis in Diagrams..
^ Check for other low voltage conditions.
^ Test the charging system. Refer to Charging System Check in Engine Electrical.
^ Possible low voltage condition causes may include:
- charging system malfunction
- excessive battery draw
- weak battery
- faulty system ground

TEST DESCRIPTION
The numbers below refer to step numbers on the diagnostic table.
4. Checks for a good ground.
6. Checks for battery voltage.