Fixed and Moveable Windows

DTC B1420

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.

DTC Descriptor
DTC B1420
- Device Voltage

Diagnostic Fault Information





Circuit/System Description

The driver door module (DDM) and passenger door module (PDM) check for proper system voltage of 9-16 volts at least once every 20 milliseconds.

Conditions for Running the DTC

Battery voltage must be between 9-16 volts.

Conditions for Setting the DTC

While attempting a power window OPEN or CLOSE command, the DDM and/or PDM detects the voltage is below 9 volts or above 15.9 volts for greater than 5 seconds.

Action Taken When the DTC Sets

The power windows will be inoperative

Conditions for Clearing the DTC

* The DTC will be current for as long as the fault is present.
* When the fault is no longer present, the DTC will be a history DTC.
* A history DTC will clear after 50 ignition cycles.

Reference Information
Schematic Reference

Moveable Window Schematics ([1][2]Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Power Windows Description and Operation (Power Windows Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information

Circuit/System Verification

Ignition ON, observe the scan tool Battery Voltage Signal parameter while commanding the power windows to OPEN and CLOSE by using the driver window switch. The parameter should be between 9.6-13.6 volts.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the appropriate door module.
2. Ignition ON, test for 9.6-13.6 volts between the B+ circuit terminal 20 and ground.

• If less than the specified range, test the B+ circuit for a an open/high resistance. If the circuit tests normal, replace the door module.
• If the circuit tests normal and the system voltage is less than or greater than the specified range, refer to Charging System Test (Charging System Test).

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

Control Module References (Programming and Relearning) for DDM or PDM replacement, setup, and programming