Chevrolet Silverado / GMC Sierra. Service manual — part 1310

If any of the resistance measurements for the individual switches are not within the
listed resistance values, replace the cruise control switch assembly.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Steering Wheel Control Switch Assembly Replacement

Control Module References for BCM replacement, setup, and programming

DTC B0835

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.

DTC Descriptor

DTC B0835 00

Cruise Control System Active Indicator Circuit

Diagnostic Fault Information

Function Switch

Minimum Resistance

Value

Maximum Resistance

Value

OFF

O.L.

O.L.

ON

6.6k Ohms

7.0k Ohms

-/SET

2.1k Ohms

2.5k Ohms

+/RES

3.6k Ohms

4.0k Ohms

Cancel

1.3k Ohms

1.7k Ohms

Circuit

Short to

Ground

Open/High

Resistance

Short to

Voltage

Signal

Performance

Cruise Control Indicator
Dimming Control

1

2

B0835 00

-

1. Cruise Control Switch Indicator Dimming Inoperative

2008 Chevrolet Silverado 1500

2008 ENGINE Cruise Control - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

Circuit/System Description

The cruise control switch contains an LED that illuminates to indicate the cruise control system
has been switched ON. Voltage is applied through the ON/OFF switch to the LED when the
switch is pressed. The BCM provides the ground path for the LED through a dedicated dimming
control circuit. Pressing the switch again opens the switch and the lamp turns OFF.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

The BCM detects excessive current in the cruise control indicator dimming signal circuit.

The above condition is present for greater than 5 seconds.

Action Taken When the DTC Sets

The BCM stores DTC B0835 in memory.

The cruise control system becomes inoperative.

Conditions for Clearing the DTC

The DTC becomes history when the conditions for setting the DTC are no longer present.

The history DTC clears after 50 malfunction-free warm-up cycles.

Reference Information

Schematic Reference

Cruise Control Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Cruise Control Description and Operation

2. Cruise Control Switch Indicator Inoperative

2008 Chevrolet Silverado 1500

2008 ENGINE Cruise Control - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

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

Ignition ON, observe the cruise control indicator while applying the cruise On/Off switch. The
indicator should turn on and off accordingly with the applied switch.

Circuit/System Testing

Disable the inflatable restraint steering wheel module when performing this diagnostic. Refer to
SIR Disabling and Enabling .

1. Ignition OFF, remove the inflatable restraint steering wheel module. Refer to Inflatable

Restraint Steering Wheel Module Replacement .

2. Disconnect the harness connector at the cruise control switch assembly.

3. Ignition ON, test for 0 volts between the cruise control harness connector terminal 9 and

ground.

If voltage is present, test the circuit for a short to voltage.

4. If the circuit tests normal, replace the BCM.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM replacement, setup, and programming

DTC P0571

CAUTION: Refer to SIR Caution .

2008 Chevrolet Silverado 1500

2008 ENGINE Cruise Control - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

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.

DTC Descriptor

DTC P0571 00

Cruise Control Brake Switch Circuit

Diagnostic Fault Information

Circuit/System Description

The brake switch signal circuit is a high voltage input to the body control module (BCM), engine
control module (ECM), transmission control module (TCM), Power Take Off (PTO) module (if
equipped) and Trailer Brake controller (if equipped). The BCM monitors the stop lamp switch
circuit to detect when the brake pedal has been applied. The ECM monitors the brake switch
signal to determine when the brake pedal is applied. When the brake pedal is applied, the BCM
sends a GMLAN serial data message to the ECM indicating that the brake pedal has been
applied. The ECM senses a high voltage signal on the brake switch signal circuit when the stop
lamp switch is closed.

Conditions for Running the DTC

The ignition is ON.

The engine is running.

Battery voltage is greater than 11.5 volts.

Conditions for Setting the DTC

The ECM detects a low voltage signal on the brake switch signal circuit when the serial data
message from the BCM indicates the brakes are applied.

Action Taken When the DTC Sets

Circuit

Short to

Ground

Open/High

Resistance

Short to

Voltage

Signal

Performance

Brake Switch Signal

P0571

P0571

-

P0571

2008 Chevrolet Silverado 1500

2008 ENGINE Cruise Control - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado