ABS - Integrated Chassis Control

DTC C1236: Low System Voltage:

DTC C1236 Schematic:

CIRCUIT DESCRIPTION
This circuit is used to monitor the voltage level available to the EBTCM. If the voltage drops below 10.5 volts, full performance of the ABS/TCS/ICCS cannot be guaranteed. During ABS/TCS/ICCS operation, there are several current requirements that will cause battery voltage to drop. Because of this, voltage is monitored prior to ABS/TCS/ICCS operation to indicate good charging system condition and also during ABS/TCS/ICCS operation when voltage may drop significantly.

CONDITION FOR SETTING THE DTC
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
A malfunction DTC is stored, ABS/TCS/ICCS is disabled and the ABS and TRACTION CONTROL Indicator lamps are turned ON. Vehicles with ICCS2 will display the STABILITY REDUCED message on the DIC.

CONDITIONS FOR CLEARING THE DTC
Condition for DTC is no longer present and scan tool clear DTC function is used. Fifty start 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. An intermittent malfunction is most likely caused by a poor connection, rubbed through insulation, or a wire that is broken inside the insulation.

TEST DESCRIPTION
The numbers below refer to step numbers on the diagnostic table.
3. Checks is EBTCM terminal B a good ground.
5. Checks is EBTCM terminal A at battery voltage.