Chevrolet Silverado / GMC Sierra. Manual — part 1539

5. If the circuits test normal replace the BCM.

Rear Door Lock Actuator Circuit Test

1. Verify that a test lamp connected to battery voltage illuminates when connected to each of

the lock and unlock 1 and 2 fuses in the IP fuse block.

If the test lamp does not illuminate at all 4 fuses replace the IP fuse block.

2. Disconnect the affected rear door latch connector and connect a test lamp across the lock

actuator control circuit terminals.

3. Verify that the test lamp illuminates briefly when a lock and unlock switch is activated.

If the test lamp does not illuminate in both switch positions test the lock actuator
control circuits for an open/high resistance or short to ground. If the circuits test
normal replace the IP fuse block.

4. If the circuits test normal replace the affected door latch.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Rear Door Lock Replacement (Extended Cab Upper) or Rear Door Lock
Replacement (Crew Cab) or Rear Door Lock Replacement (Extended Cab Lower)

Instrument Panel Electrical Center or Junction Block Replacement - Left Side

Control Module References for BCM replacement, programming, and setup

REPAIR INSTRUCTIONS

LOCK CYLINDER BINDING

In many cases, applying the proper lubrication can correct the following conditions:

Binding or sticking door lock cylinders

Difficulty in inserting and removing the keys

For lubricating the above components, use lubricant GM P/N 12346241 or equivalent.

Do not use penetrating lubricants such as GM P/N 1052949 or WD-40®. Penetrating lubricants
wash out the original lubrication. Penetrating lubricants eventually evaporate, leaving little or no
lubricating material. However, when using penetrating lubricants in order to thaw or in order to
loosen the lock cylinder components, refer to steps 2-4 in the procedure below for the proper

2008 Chevrolet Silverado 1500

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

Silverado

methods of lubrication.

Repair lock cylinders frozen in cold weather by using the following procedure:

1. While carefully avoiding damage to the painted surfaces, apply heat to the cylinder with a

heat gun.

2. Using a paper clip or a similar item, hold the door shutter open.

Force air into the cylinders using compressed air through a blow gun attachment.

3. While holding the shutter door open, inject small amounts of a recommended lubricant into

the cylinder.

4. Work the key into the cylinder repeatedly.

Wipe away any excess lubrication from the key.

DOOR LOCK CYLINDER REPLACEMENT

Fig. 9: View Of Front Side Door Lock Cylinder & Components
Courtesy of GENERAL MOTORS CORP.

2008 Chevrolet Silverado 1500

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

Silverado

ENDGATE LOCK CYLINDER REPLACEMENT

Fig. 10: View Of Endgate Lock Cylinder & Retaining Clip
Courtesy of GENERAL MOTORS CORP.

Callout

Component Name

Preliminary Procedures

1. Position the door window as needed for service.

2. Remove the door trim panel. Refer to Front Side Door Trim Panel Replacement

(YE9) or Front Side Door Trim Panel Replacement (SLT) .

3. Remove the water deflector. Refer to Front Side Door Water Deflector

Replacement .

4. Remove the outside door handle. Refer to Front Side Door Outside Handle

Replacement.

1

Front Side Door Lock Rod

2

Front Side Door Lock Cylinder Pawl Retainer Clip
Tip: Remove the clip that attaches the cylinder to the door handle.

3

Front Side Door Lock Cylinder Pawl

4

Front Side Door Lock Cylinder

2008 Chevrolet Silverado 1500

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

Silverado