Chevrolet Silverado / GMC Sierra. Service manual — part 2789

3. Adjust the sunroof window panel as necessary. Refer to Sunroof Window Height and

Opening Fit Adjustment.

Tighten: Tighten the screws to 3 N.m (27 lb in).

DESCRIPTION AND OPERATION

SUNROOF DESCRIPTION AND OPERATION

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.

NOTE:

Refer to Fastener Notice .

2008 Chevrolet Silverado 1500

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

2008 BRAKES

Trailer Brake Controls - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

SPECIFICATIONS

FASTENER TIGHTENING SPECIFICATIONS

SCHEMATIC AND ROUTING DIAGRAMS

TRAILER BRAKE CONTROL SCHEMATICS

Fig. 1: Module Power and Ground
Courtesy of GENERAL MOTORS CORP.

Application

Specification

Metric

English

Trailer Brake Control Module Bolt

9 N.m

80 lb in

Trailer Brake Control Relay Bolt

9 N.m

80 lb in

2008 Chevrolet Silverado 1500

2008 BRAKES Trailer Brake Controls - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

2008 Chevrolet Silverado 1500

2008 BRAKES Trailer Brake Controls - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

Fig. 2: Trailer Brake Controls
Courtesy of GENERAL MOTORS CORP.

DIAGNOSTIC INFORMATION AND PROCEDURES

DIAGNOSTIC CODE INDEX

DIAGNOSTIC CODE INDEX

DTC

Description

DTC B3894

B3894 5A: Stop Lamp Switch Circuit Plausibility Failure

DTC C0561

C0561 F0: System Disabled Information Stored Invalid Serial

Data Received

C0561 F1: System Disabled Information Stored Invalid Serial

Data Received

DTC C056D or C056E

C056D 33: ECU Hardware Performance Special Memory

Failure

C056D 34: ECU Hardware Performance RAM Failure

C056D 35: ECU Hardware Performance ROM Failure

C056D 36: ECU Hardware Performance EEPROM Failure

2008 Chevrolet Silverado 1500

2008 BRAKES Trailer Brake Controls - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

DIAGNOSTIC STARTING POINT - TRAILER BRAKE CONTROLS

Begin the system diagnosis with 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 diagnostic trouble codes (DTCs) and their status

The use of the Diagnostic System Check will identify the correct procedure for diagnosing the

C056D 39: ECU Hardware Performance Internal Electronic

Failure (ECU processor failure)

C056E 41: ECU Software Performance Operational

Software/Calibration Set Not Programmed

DTC C0800

C800 03: Device Power Circuit Voltage Below Threshold
C800 07: Device Power Circuit Voltage Above Threshold

DTC C0845

C0845 03: Device Ignition 1 Circuit Voltage Below Threshold

DTC C0870

C0870: Device Voltage Reference Output 1 Circuit

DTC C0880

C0880: Device Voltage Reference Output 2 Circuit

DTC C0890

C0890: Device Voltage Reference Output 3 Circuit

DTC C1112

C1112: Trailer Brake Control Relay Low Control Circuit -

Relay Control Active Low

DTC C1113

C1113 01: Trailer Brake Control Relay High Control Circuit

Short to Battery

DTC C1114

C1114: Trailer Brake Control Solenoids Control Circuit-

Trailer Auxiliary Supply Voltage

DTC C1115

C1115 08: Manual Trailer Brake Apply Request Switch Signal

Invalid-Manual Apply Switch Stuck Closed

C1115 5A: Manual Trailer Brake Apply Request Switch Signal

Plausibility Failure

DTC C1116

C1116: Manual Trailer Brake Apply Request Signal 1

DTC C1117

C1117: Manual Trailer Brake Apply Request circuit Signal 2-

Redundant Manual Apply Signal

DTC C1118

C1118: Trailer Brake Control Sensitivity Switch Circuit

C1118 08: Trailer Brake Control Sensitivity Switch Circuit

Signal Invalid

DTC C1119

C1119: Trailer Brake Control Relay Feedback Circuit

2008 Chevrolet Silverado 1500

2008 BRAKES Trailer Brake Controls - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado