1010-09

1010-09 BCM SYSTEM UNDERVOLTAGE





When Monitored and Set Condition

- When Monitored: Ignition on. The Body Control Module (BCM) monitors the Fused B(+) circuit voltage for proper system voltage.
- Set Condition: If the battery voltage falls below 9.6 volts, the Diagnostic Trouble Code (DTC) is set.





For a complete Body Control Module Circuit Diagram. Body - Electrical Diagnostics.

Diagnostic Test

1. WITH THE SCAN TOOL READ DTCs
Turn the ignition on.
With the scan tool, read and record the BCM DTCs.
With the scan tool, erase the BCM DTCs.
Start the engine.
With the scan tool, read DTCs.
Does the scan tool display a System Undervoltage DTC?

Yes

- Go To 2

No

- Go To 4
- The condition that caused this DTC to set is currently not present. Inspect the related wiring harness for a possible intermittent condition.

2. MEASURE THE BATTERY VOLTAGE




Measure the battery voltage with the engine running.
Is the battery voltage below 10 volts?

Yes

- Refer to charging system testing and repair.
- Perform BODY VERIFICATION TEST. Body Verification Test

No

- Go To 3

3. MEASURE THE VOLTAGE OF THE FUSED B(+) CIRCUIT




Turn the ignition off.
Disconnect the BCM harness connector.

NOTE: Check connectors - Clean/repair as necessary.

Turn the ignition on.
Measure the voltage of all Fused B(+) circuits at the BCM C4 harness connector.
Is the voltage above 10 volts at each circuit?

Yes

- Replace the Body Control Module.Body Control Module - Removal.

No

- Repair the Fused B(+) circuit for an open.
- Perform BODY VERIFICATION TEST. Body Verification Test

4. INTERMITTENT WIRING AND CONNECTORS
The condition that caused this DTC to set is currently not present. Inspect the related wiring harness for a possible intermittent condition.

NOTE: Check connectors - Clean/repair as necessary. Poor pin to terminal connections can set DTC's.

NOTE: Check for any Technical Service Bulletins that may apply.

Using the wiring diagram/schematic as a guide, inspect the wiring and connectors specific to this DTC. Wiggle the wires while checking for shorts and open circuits.
Were there any problems found?

Yes

- Repair as necessary.
- Perform BODY VERIFICATION TEST. Body Verification Test

No

- The condition that caused this DTC to set is currently not present. Inspect the related wiring harness for a possible intermittent condition.