Diagnostic Instructions
DTC Descriptor
DTC B3821 00: Left Rear Window Relay Power Circuit
Circuit/System Description
Accessory/RAP voltage is supplied to the left rear power window switch through the window lockout signal circuit. If the window lockout function is disabled, the body control module (BCM) supplies voltage to the rear window switches allowing for normal
window operation from the rear switches. If the window lockout function is enabled, the BCM will not supply voltage to the rear window switches and the rear windows will only operate from the driver power window switch through the BCM up and down signal circuits.
Conditions for Running the DTC
| • | Battery voltage is between 9-16 volts. |
| • | The ignition switch is in the ON position. |
| • | The window lockout function is disabled |
Conditions for Setting the DTC
The left rear window lockout circuit is shorted to ground.
Action Taken When the DTC Sets
The left rear power window will be inoperative.
Conditions for Clearing the DTC
| • | When the fault is no longer present the DTC will be a history status code. |
| • | The history code will clear after 50 fault free ignition cycles or by using the scan tool clear DTCs feature. |
Reference Information
Schematic Reference
Moveable Window Schematics
Connector End View Reference
Description and Operation
Power Windows Description and Operation
Electrical Information Reference
Scan Tool Reference
Circuit/System Testing
- Disconnect the left rear window switch connector and connect a test lamp from the lockout signal circuit to ground.
- Ignition ON, verify that the test lamp illuminates while the rear window lockout function is inactive.
| ⇒ | If the test lamp does not illuminate test the left rear window lockout signal circuit for a short to ground. If the circuit tests normal replace the BCM. |
- If the circuits test normal replace the left rear window switch.
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.
