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/Active Handling (if equipped with RPO JL4) cannot be guaranteed. During ABS/TCS/Active Handling operation, there are several current requirements that will cause battery voltage to drop. Because of this, voltage is monitored prior to ABS/TCS/Active Handling operation to indicate good charging system condition and also during ABS/TCS/Active Handling operation when voltage may drop significantly.

CONDITIONS FOR SETTING THE DTC
Diagnostic Trouble Code (DTC) C1236 can only be set if the vehicle's speed is greater than 8 km/h (5 mph). If both the battery and ignition voltages are less than 10.5 volts, a malfunction DTC will set.

ACTION TAKEN WHEN THE DTC SETS
ABS/TCS/Active Handling (if equipped with RPO JL4) are disabled.
^ Indicators that turn on:
- ABS indicator
- Car Icon (TCS indicator)
^ Messages displayed on the Driver Information Center (DIC):
- Service ABS
- Service Traction System
- Service Active HNDLG (if equipped with Active Handling RPO JL4)

CONDITIONS FOR CLEARING THE DTC
^ Condition for Diagnostic Trouble Code (DTC) is no longer present and Scan Tool clear DTC function is used.
^ 50 Ignition cycles have passed with no DTCs detected.

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.
^ If an intermittent malfunction exists refer to Testing for Electrical Intermittents in Diagnostic Aids.
^ Check for other low voltage conditions.
^ Test the charging system.
^ Possible causes for Diagnostic Trouble Code (DTC) C1236 to set:
- 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.





DTC C1236 LOW SYSTEM SUPPLY VOLTAGE