Circuit Description
The body control module (BCM) has an internal voltage sensor with a dedicated circuit that checks the battery positive voltage and battery negative circuit voltage to determine if it is below 18.0 volts.
Conditions for Running the DTC
This DTC shall run only if the BCM has power, ground and the ignition is not in START mode. This DTC shall execute regardless of the battery voltage.
Conditions for Setting the DTC
This DTC shall be set as current when the voltage raises above 18.0 volts for 1200 milliseconds.
Action Taken When the DTC Sets
| • | The ECM will not illuminate the charge indicator. |
| • | This DTC shall be set as current when the voltage raises above 18.0 volts for 1200 milliseconds. |
A message shall be sent out on the class 2 lines to notify all other modules of low battery voltage.
Conditions for Clearing the MIL/DTC
In order to clear the DTC from a current status the ignition must be cycled and the voltage shall be less than 18.0 volts.
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Engine Electrical Diagnostic System Check? | -- | Go to Step 2 | |
2 |
Does the scan tool indicate the battery voltage is less than the specified value? | 18.0 V | Go to Step 4 | Go to Step 3 |
Are the voltages within the specified value? | 1.0 V | Go to Charging System Test | Go to Step 4 | |
4 | Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 6 | Go to Step 5 |
5 |
Important: Perform the setup procedure for the BCM. Replace the BCM. Refer to Body Control Module Replacement . Did you complete the replacement? | -- | Go to Step 6 | -- |
6 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
