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/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
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 DIC: |
| - | Service ABS |
| - | Service Traction System |
| - | Service Active HNDLG (if equipped with Active Handling RPO JL4) |
Conditions for Clearing the DTC
| • | Condition for 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 Wiring Systems. |
| • | Check for other low voltage conditions. |
| • | Test the charging system. Refer to Charging System Check in Engine Electrical. |
| • | Possible causes for 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.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the Diagnostic System Check performed? | -- | ||
2 | Check the charging system. Refer to Charging System Check in Engine Electrical. Is the Charging System OK? | -- | Go to Battery Common Causes of Malfunction in Engine Electrical | |
3 |
Is their evidence of any corrosion or damage? | -- | ||
Is the resistance within the range specified in the value(s) column? | 0-2ohms | |||
5 | Measure the voltage between terminals D and B of J 39700 . Is the voltage within the range specified in the value(s) column? | Above 10.5 V | Go to Voltmeter Displays High or Low in Engine Electrical | |
Is the voltage within the range specified in the value(s) column? | Above 10.5 V | Go to Voltmeter Displays High or Low in Engine Electrical | ||
7 | Repair as necessary Is the repair complete? | -- | -- | |
8 | Repair open or high resistance in CKT 1251. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | -- | |
9 | Replace the EBTCM. Refer to Electronic Brake Control Module Replacement . Is the replacement complete? | -- | -- |
