Chevrolet Silverado / GMC Sierra. Service manual — part 1533

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 status code.

A history DTC will clear after 50 ignition cycles or with a scan tool using the clear DTCs
function.

Reference Information

Schematic Reference

Door Control Module Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Power Door Locks Description and Operation

Electrical Information Reference

Circuit Testing

Connector Repairs

Testing for Intermittent Conditions and Poor Connections

Wiring Repairs

Scan Tool Reference

Control Module References for Scan Tool Information

Circuit/System Verification

1. Install a scan tool and display the inputs data list of the affected door module.

If any of the integrated switch inputs are displayed as Active while in an inactive state,
replace the door module.

2. Clear the DTCs.

3. Activate all of the integrated switch functions.

If the DTC resets, replace the affected door module.

Repair Procedures

2008 Chevrolet Silverado 1500

2008 ACCESSORIES & EQUIPMENT Vehicle Access - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for driver or passenger door loch and side window switch
replacement, programming, and setup.

DTC B3125

Diagnostic Instructions

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Review Strategy Based Diagnosis for an overview of the diagnostic approach

Diagnostic Procedure Instructions provides an overview of each diagnostic category

DTC Descriptor

DTC B3125 00

Driver Door Only Unlock Circuit

Circuit/System Description

The body control module (BCM) energizes the driver door unlock relay coil through a low side
drive control circuit. When the BCM receives an unlock message the driver door unlock relay
control circuit is grounded energizing the driver door unlock relay coil.

Conditions for Running the DTC

Battery voltage is between 9-16 volts.

The BCM has attempted to energize the unlock relay.

Conditions for Setting the DTC

The driver door unlock relay control circuit is shorted to voltage.

Action Taken When the DTC Sets

The BCM will not attempt unlock operation.

Conditions for Clearing the DTC

When the output request is not active 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.

2008 Chevrolet Silverado 1500

2008 ACCESSORIES & EQUIPMENT Vehicle Access - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado

Reference Information

Schematic Reference

Door Lock/Indicator Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Power Door Locks Description and Operation

Electrical Information Reference

Circuit Testing

Connector Repairs

Testing for Intermittent Conditions and Poor Connections

Wiring Repairs

Scan Tool Reference

Control Module References for Scan Tool Information

Circuit/System Testing

1. Disconnect the BCM connector X7 and connect a test lamp from terminal 6 to ground.

2. Ignition ON, verify that the test lamp does not illuminate.

If the test lamp illuminates test the control circuit for a short to voltage. If the circuit
tests normal replace the IP fuse block.

3. If the circuits test normal replace the BCM.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Instrument Panel Electrical Center or Junction Block Replacement - Left Side

Control Module References for BCM replacement, programming, and setup.

DTC B3130

2008 Chevrolet Silverado 1500

2008 ACCESSORIES & EQUIPMENT Vehicle Access - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado

Diagnostic Instructions

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Review Strategy Based Diagnosis for an overview of the diagnostic approach

Diagnostic Procedure Instructions provides an overview of each diagnostic category

DTC Descriptor

DTC B3130 00

All Door Unlock Circuit

Circuit/System Description

The body control module (BCM) energizes the unlock relay coil through a low side drive control
circuit. When the BCM receives an unlock message the door unlock control circuit is grounded
energizing the unlock relay coil.

Conditions for Running the DTC

Battery voltage is between 9-16 volts.

The BCM has attempted to energize the unlock relay.

Conditions for Setting the DTC

The door unlock control circuit is shorted to voltage.

Action Taken When the DTC Sets

The BCM will not attempt unlock operation.

Conditions for Clearing the DTC

When the output request is not active 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

Door Lock/Indicator Schematics

2008 Chevrolet Silverado 1500

2008 ACCESSORIES & EQUIPMENT Vehicle Access - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado