Chevrolet Silverado / GMC Sierra. Service manual — part 2661

Control circuit terminal 2

If less than the specified value, test the appropriate circuit for a short to ground. If the
circuits test normal, test or replace the rearview mirror motor.

4. Test for 5-15 ohms of resistance between the control circuit terminal 1 and the control

circuit terminal 2.

If not within the specified range, test both control circuits for an open/high resistance.
If the circuits test normal, test or replace the rearview mirror motor.

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

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Outside Rearview Mirror Motor Replacement

Control Module References for DDS or PDS replacement, setup, and programming

SYMPTOMS - MIRRORS

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:

Outside Mirror Description and Operation (Heated Mirrors)Outside Mirror
Description and Operation (Power Mirrors)

Automatic Day-Night Mirror Description and Operation

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.

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

tables.

2008 Chevrolet Silverado 1500

2008 ACCESSORIES & EQUIPMENT Mirrors - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

Intermittent

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

Symptom List

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

Heated Mirrors Inoperative

Automatic Day-Night Mirrors Inoperative (With RPO DL3/DR4) or Automatic Day-
Night Mirrors Inoperative (Without RPO DL3/DR4)

Power Mirror Folding Inoperative

Power Mirrors Inoperative

HEATED MIRRORS INOPERATIVE

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.

Diagnostic Fault Information

Circuit/System Description

The Driver Door Switch (DDS) and Passenger Door Switch (PDS) supply voltage to the outside
rearview mirror heater elements upon receipt of a serial data message from the HVAC module
indicating that the rear defrost system is active. The door switch supplies B+ through the
driver/passenger mirror heating element supply voltage circuit when a request is seen. Ground is
applied through the driver/passenger mirror heating low reference circuit.

Circuit

Short to

Ground

Open/High

Resistance

Short to

Voltage

Signal

Performance

Mirror Heating Element
Supply Voltage

B1640 02

1

B1640 01

-

Low Reference

-

1

1

-

1. Heated Mirror Malfunction

2008 Chevrolet Silverado 1500

2008 ACCESSORIES & EQUIPMENT Mirrors - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

Reference Information

Schematic Reference

Outside Rearview Mirror Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Outside Mirror Description and Operation (Heated Mirrors) or Outside Mirror
Description and Operation (Power Mirrors)

Electrical Information Reference

Circuit Testing

Connector Repairs

Testing for Intermittent Conditions and Poor Connections

Wiring Repairs

Sacn Tool Reference

Control Module References For Scan Tool Information.

Circuit/System Verification

1. Ignition ON, press the rear window defogger switch. Verify the rear window defogger

indicator illuminates.

If the rear window defogger indicator does not illuminate, refer to Rear Window
Defogger Malfunction .

2. Rear window defogger ON, verify both the left and right outside mirror glass become warm.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector X3 at the appropriate door switch.

2. Ignition ON, verify a test lamp does not illuminate between the supply voltage circuit

terminal 7 and ground.

If the test lamp illuminates, test the supply voltage circuit for a short to voltage.

2008 Chevrolet Silverado 1500

2008 ACCESSORIES & EQUIPMENT Mirrors - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

3. Ignition OFF, test for infinite resistance between the supply voltage circuit terminal 7 and

ground.

If less than the specified value, test the supply voltage circuit for a short to ground. If
the circuit tests normal, test or replace the applicable rearview mirror face.

4. Test for 5-10 ohms of resistance between the supply voltage circuit terminal 7 and the low

reference circuit terminal 3.

If not within the specified range, test the supply voltage circuit and the low reference
circuit for an open/high resistance. If the circuits test normal, test or replace the
appropriate rearview mirror face.

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

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Outside Rearview Mirror Glass Replacement

Control Module References for DDS or PDS replacement, setup and programming

AUTOMATIC DAY-NIGHT MIRRORS INOPERATIVE (WITH RPO DL3/DR4)

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.

Diagnostic Fault Information

Circuit/System Description

Circuit

Short to

Ground

Open/High

Resistance

Short to

Voltage

Signal

Performance

Backup Lamp Supply Voltage

1

1

2

-

Automatic Day/Night Mirror
Signal

2

2

1

-

Low Reference

-

2

2

-

1. Rearview mirror remains dimmed in reverse
2. Rearview mirror does not dim

2008 Chevrolet Silverado 1500

2008 ACCESSORIES & EQUIPMENT Mirrors - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado