Window System Diagnosis

DTC B1420

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

DTC DESCRIPTOR

DTC B1420
Device Voltage

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. When the DDM or PDM detects that system voltage is either below 9 volts or above 16 volts, a DTC is set and DTC updates are disabled.

CONDITIONS FOR RUNNING THE DTC
Battery voltage must be between 9-16 volts.

CONDITIONS FOR SETTING THE DTC
The DDM or PDM detects system voltage is below 9 volts or above 16 volts.

ACTIONS TAKEN WHEN THE DTC SETS
DTC updates are disabled.

CONDITIONS FOR CLEARING THE DTC
- The condition responsible for setting the DTC no longer exists.
- You issue a scan tool CLEAR DTCs command.

DIAGNOSTIC AIDS
- DTC B1420 may set during vehicle startup if the vehicle system voltage falls bellow 9 volts.
- The Starting/Charging system may be the cause of an intermittent malfunction.

CIRCUIT/SYSTEM TESTING
1. Ignition OFF, disconnect the appropriate door control module harness connector.
2. Test for less than 1.0 ohm of resistance between the ground circuit terminal 10 and ground.
- If greater than the specified range, test the ground circuit for an open/high resistance.
3. If all circuits test normal, replace the appropriate door control module.

REPAIR INSTRUCTIONS
Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

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