Chevrolet Silverado / GMC Sierra. Service manual — part 2359

BRAKE SYSTEM SPECIFICATIONS

SCHEMATIC AND ROUTING DIAGRAMS

HYDRAULIC BRAKE SCHEMATICS

Fig. 1: Hydraulic Brake Schematic
Courtesy of GENERAL MOTORS CORP.

DIAGNOSTIC INFORMATION AND PROCEDURES

Application

Specification

Metric

English

Brake Pedal Maximum Travel*

Vacuum Power Assist

60 mm

2.36 in

Hydraulic Power Assist

90 mm

3.54 in

* Specification with 445 N (100 lbs) of force applied to the brake pedal, the ignition OFF,
and the brake booster power reserve depleted.

2008 Chevrolet Silverado 1500

2008 BRAKES Hydraulic Brakes - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

DIAGNOSTIC CODE INDEX

DIAGNOSTIC CODE INDEX

DIAGNOSTIC STARTING POINT - HYDRAULIC BRAKES

Begin the system diagnosis by reviewing the system Description and Operation. Reviewing the
Description and Operation information will help you determine the correct symptom diagnostic
procedure when a malfunction exists. Reviewing the Description and Operation information will
also help you determine if the condition described by the customer is normal operation. Refer to
Symptoms - Hydraulic Brakes in order to identify the correct procedure for diagnosing the
system and where the procedure is located.

DTC C0267

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 C0267 00

Low Brake Fluid Indicated

Diagnostic Fault Information

Circuit/System Description

The brake fluid level switch monitors the level of brake fluid in the master cylinder. When the

DTC

Description

DTC C0267

C0267 00: Low Brake Fluid Indicated

Circuit

Short to

Ground

Open/High

Resistance

Short to

Voltage

Signal

Performance

Brake Fluid Level Signal

C0267 00

1

1

-

Park Brake Signal

1

1

1

-

Ground

-

1

-

-

1. Brake Warning Indicator Malfunction

2008 Chevrolet Silverado 1500

2008 BRAKES Hydraulic Brakes - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

instrument panel cluster (IPC) sees the brake fluid level switch input closed, it turns ON the Red
Brake Warning indicator and sends a serial data message to the electronic brake control module
(EBCM) that the brake fluid level is low.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

Low brake fluid is detected.

A short to ground exists on the signal circuit.

Action Taken When the DTC Sets

The EBCM disables the antilock brake system (ABS)/traction control system (TCS)
dynamic rear proportion (DRP) and vehicle stability enhancement system (VSES).

The ABS indicator illuminates.

The StabiliTrak indicator illuminates.

The Red Brake Warning indicator illuminates.

Conditions for Clearing the DTC

The condition for the DTC is no longer present.

The EBCM clears the history DTC when a current DTC is not detected in 100 consecutive
drive cycles.

Reference Information

Schematic Reference

Hydraulic Brake Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Brake Warning System Description and Operation

Electrical Information Reference

2008 Chevrolet Silverado 1500

2008 BRAKES Hydraulic Brakes - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

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. Inspect for proper brake fluid level, the fluid level should be at or above the proper level.

If low, refer to Brake Fluid Loss.

2. Ignition ON, observe the scan tool IPC Brake Fluid parameter. The reading should be OK.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the brake fluid level switch.

2. Test for less than 1 ohm between the ground circuit terminal A and ground.

If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, verify the scan tool IPC Brake Fluid parameter is Ok.

If not the specified value, test the signal circuit for a short to ground. If the circuit tests
normal, replace the IPC.

4. Install a 3A fused jumper wire between the signal circuit terminal B and ground. Verify the

scan tool IPC Brake Fluid parameter is Low.

If not the specified value, test the signal circuit for a short to voltage or an open/high
resistance. If the circuit tests normal, replace the IPC.

5. If all circuits test normal, test or replace the brake fluid level switch.

Component Testing

1. Ignition OFF, disconnect the harness connector at the brake fluid level switch.

2. Test for infinite resistance between the ground terminal A and the signal terminal B.

If less than the specified value, replace the brake fluid level switch.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

2008 Chevrolet Silverado 1500

2008 BRAKES Hydraulic Brakes - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado