Chevrolet Silverado / GMC Sierra. Service manual — part 1535

Conditions for Running the DTC

Battery voltage is between 9-16 volts.

Conditions for Setting the DTC

A door lock or unlock switch input to the BCM is active for greater than 60 seconds.

Action Taken When the DTC Sets

The input signal will be ignored by the BCM for as long as the code is current.

Conditions for Clearing the DTC

When the input signal has inactive for 2.5 seconds 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.

Diagnostic Aids

A current switch code indicates that the switch is stuck or the signal circuit is shorted to ground.

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

2008 Chevrolet Silverado 1500

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

Silverado

Scan Tool Reference

Control Module References for Scan Tool Information

Circuit/System Verification

Observe the scan tool door lock and unlock switch parameters while operating the switch to the
lock and unlock positions. The readings should change from inactive to active.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the door lock switch.

2. Test for less than 1 ohm of resistance between the ground circuit terminal B and ground.

If greater than the specified range, test the ground circuit for an open/high resistance.

3. Verify the scan tool door lock and unlock switch parameters are inactive.

If not the specified value, test the signal circuit listed below for a short to ground. If
the circuit tests normal, replace the BCM.

Lock terminal D

Unlock terminal E

4. Install a 3A fused jumper wire between the signal circuits listed below and the ground

circuit terminal B. Verify the scan tool door lock and unlock switch parameters are active.

Lock terminal D

Unlock terminal E

If not the specified value, test the signal circuit for a short to voltage or an open/high
resistance. If the circuit tests normal, replace the BCM.

5. If all circuits test normal, test or replace the door lock switch.

Component Testing

1. Ignition OFF, disconnect the harness connector at the door lock switch.

2. Test for infinite resistance between the signal terminal listed below and the ground terminal

B with the switch in the open position.

Lock terminal D

Unlock terminal E

If not the specified value, replace the door lock switch.

3. Test for less than 1 ohm between the signal terminal listed below and the ground terminal B

with the switch in the closed position.

2008 Chevrolet Silverado 1500

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

Silverado

Lock terminal D

Unlock terminal E

If greater than the specified range, replace the door lock switch.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Door Lock and Side Window Switch Replacement - Driver Side

Door Lock and Side Window Switch Replacement - Passenger Side

Control Module References for BCM replacement, programming, and setup

SYMPTOMS - VEHICLE ACCESS

1. Perform the Diagnostic System Check - Vehicle before using the Symptom Tables in

order to verify that all of the following are true:

There are no DTCs set.

The control modules can communicate via the serial data link.

2. Review the system operation in order to familiarize yourself with the system functions.

Refer to the following system descriptions:

Power Door Locks Description and Operation

Door Ajar Indicator Description and Operation (w/AN3)Door Ajar Indicator
Description and Operation (w/o AN3)

Visual/Physical Inspection

Inspect for aftermarket devices which could affect the operation of the system. Refer to
Checking Aftermarket Accessories .

Inspect the easily accessible or visible system components for obvious damage or conditions
which could cause the symptom.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to
Testing for Intermittent Conditions and Poor Connections .

IMPORTANT: The following steps must be completed before using the symptom

tables.

2008 Chevrolet Silverado 1500

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

Silverado

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the
symptom:

Door Ajar Indicator Malfunction (w/AN3) or Door Ajar Indicator Malfunction (w/o
AN3)

Power Door Locks Inoperative - Front (w/AN3) or Power Door Locks Inoperative -
Front (w/o AN3)

Power Door Locks Inoperative - Rear

DOOR AJAR INDICATOR MALFUNCTION (W/AN3)

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

Circuit/System Description

The driver door switch (DDS) and the passenger door switch (PDS) receive a discrete input from
the driver door ajar switch and the passenger door ajar switch respectively. Likewise, the body
control module (BCM) receives a discrete input from both the left and right rear door ajar
switches. The door ajar switches are normally open when the doors are fully closed. When a door
is opened, the door ajar switch contacts close providing a path to ground. The instrument panel
cluster (IPC) receives a GMLAN serial data message from the BCM, DDS, or PDS indicating the
door ajar status and the driver information center (DIC) located at the bottom of the IPC,
illuminates the appropriate door ajar message when one of the doors is open. If this message is
displayed and the vehicle speed is greater than 8.1 km/h (5 mph), a chime will sound.

Reference Information

Schematic Reference

Instrument Cluster Schematics

Connector End View Reference

Component Connector End Views

2008 Chevrolet Silverado 1500

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

Silverado