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Chevrolet Silverado / GMC Sierra. Manual - part 2770
2008 ACCESSORIES & EQUIPMENT
Sunroof - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
SPECIFICATIONS
FASTENER TIGHTENING SPECIFICATIONS
SCHEMATIC AND ROUTING DIAGRAMS
SUNROOF SCHEMATICS
Application
Specifications
Metric
English
Sunroof Actuator to Bracket Screws
3 N.m
27 lb in
Sunroof Air Deflector Screws
3 N.m
27 lb in
Sunroof Module
10 N.m
89 lb in
Sunroof Water Tray to Sunroof Module Screws
1 N.m
9 lb in
Sunroof Window to Module Screws
3 N.m
27 lb in
2008 Chevrolet Silverado 1500
2008 ACCESSORIES & EQUIPMENT Sunroof - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
2008 Chevrolet Silverado 1500
2008 ACCESSORIES & EQUIPMENT Sunroof - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
Fig. 1: Sunroof Schematic
Courtesy of GENERAL MOTORS CORP.
DIAGNOSTIC INFORMATION AND PROCEDURES
DIAGNOSTIC STARTING POINT - ROOF
Begin the power sunroof system diagnosis with the Diagnostic System Check - Vehicle . The
Diagnostic System Check will provide the following information:
The identification of the control modules which command the system
The ability of the control modules to communicate through the serial data circuit
The identification of any stored DTCs and their status
The use of the Diagnostic System Check will identify the correct procedure for diagnosing the
system and where the procedure is located.
SYMPTOMS - ROOF
Visual/Physical Inspection
Inspect for aftermarket devices which could affect the operation of the Sunroof 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 .
Symptom List
Refer to Power Sunroof Inoperative in order to diagnose the symptom.
POWER SUNROOF INOPERATIVE
Diagnostic Instructions
IMPORTANT: Review the system description in order to familiarize yourself
with the system functions. Refer to Sunroof Description and
Operation.
2008 Chevrolet Silverado 1500
2008 ACCESSORIES & EQUIPMENT Sunroof - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
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 power sunroof is operated by the sunroof motor/actuator which consists of the motor and
electronic control unit as a complete assembly. The system is powered by a battery supply circuit
and an ignition/retained accessory power signal circuit determines when the sunroof may be
operated. The switch signal circuits are supplied battery voltage through a resistor and monitored
within the ECU. When a sunroof switch is pressed the switch signal circuit is closed to ground
and most of the voltage supplied to the signal circuit will be dropped across the resistor within
the ECU indicating the switch is active.
Diagnostic Aids
Prior to performing sunroof system circuit diagnosis, perform the Sunroof Motor/Actuator
Initialization/Teach Process (Extended Cab New Motor) or Sunroof Motor/Actuator
Initialization/Teach Process (Extended Cab Existing Motor) or Sunroof Motor/Actuator
Initialization/Teach Process (Crew Cab Existing Motor) or Sunroof Motor/Actuator
Initialization/Teach Process (Crew Cab New Motor).
Reference Information
Circuit
Short to
Ground
Open/High
Resistance
Short to
Voltage
Signal
Performance
Battery
1
1
-
-
Accessory
1
1
3
-
Close Switch Signal
1
1
1
-
Express Switch Signal
2
2
2
-
Open Switch Signal
1
1
1
-
Vent Close Switch Signal
1
1
1
-
Vent Open Switch Signal
1
1
1
-
Ground
-
1
-
-
1. Power sunroof inoperative
2. Express open and close inoperative
3. Power sunroof operates with ignition off
2008 Chevrolet Silverado 1500
2008 ACCESSORIES & EQUIPMENT Sunroof - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
Schematic Reference
Sunroof Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Sunroof 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. With the sunroof in the closed position, press the sunroof open switch. The sunroof should
open.
If the sunroof does not open, refer to Power Sunroof Malfunction below.
2. With the sunroof in the open position, press the sunroof close switch. The sunroof should
close.
If the sunroof does not close, refer to Power Sunroof Malfunction below.
3. With the sunroof in the closed position, operate the sunroof express open feature. The
sunroof should fully open.
If the express open feature does not function, refer to Power Sunroof Express Feature
Malfunction below.
4. With the sunroof in the open position, operate the sunroof express close feature. The sunroof
should fully close.
If the express close feature does not function, refer to Power Sunroof Express Feature
Malfunction below.
2008 Chevrolet Silverado 1500
2008 ACCESSORIES & EQUIPMENT Sunroof - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
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