C1236

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

CONDITIONS FOR SETTING THE DTC
DTC C1236 can only be set if the vehicle's speed is greater than 8 km/in (5 mph). If both the battery and ignition voltages are less than 10.8 volts and the vehicle is not in a ABS/TCS condition, a malfunction DTC will set. If the vehicle is in an ABS/TCS condition then the battery and ignition voltages must drop below 9.35 volts for a malfunction DTC to set.

ACTION TAKEN WHEN THE DTC SETS
^ A malfunction DTC is stored.
^ ABS/TCS is disabled.
^ ABS/TCS Indicators are turned on.

CONDITIONS FOR CLEARING THE DTC
^ Condition for DTC is no longer present and Scan Tool clear DTC function is used.
^ 100 Ignition cycles have passed with no DTCs detected.

DIAGNOSTIC AIDS
^ Possible causes for DTC C1236 to set are:
- Charging system malfunction
- Excessive battery draw
- Weak battery
- Faulty engine block ground
- Loose battery cables

^ Test the charging system.
^ Check for other low voltage conditions.
^ If an intermittent malfunction exists refer to Intermittents and Poor Connections Diagnosis in 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.