Chevrolet Silverado / GMC Sierra. Service manual — part 708

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

Diagnostic Aids

Inspect the back of the wheel bearing on the encoder surface for metal debris that could
cause an erratic reading with the sensor. Do not use a magnet to clean the debris, or damage
to the encoder ring may occur.

If 2 or more wheel speed sensors are inoperative diagnose each wheel speed sensor
individually.

An ECE 13 response may be required, after repairs are made, and DTCs are cleared,
operate the vehicle at speeds greater than 15 km/h (10 mph) to complete the self test, and
the EBCM will turn off the ABS indicator.

If the customer comments that the ABS indicator is ON only during moist environmental
conditions: rain, snow, vehicle wash, etc., inspect the wheel speed sensor wiring for signs of
water intrusion. If the DTC is not current, clear all DTCs and simulate the effects of water
intrusion by using the following procedure:

1. Spray the suspected area with a 5 percent saltwater solution. To create a 5 percent saltwater

solution, add 2 teaspoons of salt to 8 fl oz of water (10 g of salt to 200 ml of water).

2. Test drive the vehicle over various road surfaces: bumps, turns, etc., above 40 km/h (25

mph) for at least 30 seconds.

3. Rinse the area thoroughly when completed.

Reference Information

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

ABS Description and Operation (With JL4) or ABS Description and Operation (Without
JL4)

Electrical Information Reference

2008 Chevrolet Silverado 1500

2008 BRAKES Antilock Brake System - 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

Observe the scan tool Wheel Speed Sensor parameter. The reading should be the same speed on
all sensors when driving in a straight line at a speed greater than 20 km/h (13 mph).

Circuit/System Testing

It is recommended that Component Testing is performed before Circuit Testing when diagnosing
wheel speed sensors.

1. Ignition OFF, disconnect the harness connector at the EBCM.

2. Ignition ON, test for less than 1 volt between the low reference circuit terminals of the

appropriate sensor listed below and ground.

LR Sensor circuit terminal 20

RR Sensor circuit terminal 31

If greater than the specified value, test the low reference circuit for a short to voltage.
If the circuit tests normal, replace the wheel speed sensor.

3. Test for less than 1 volt between the signal circuit terminals of the appropriate sensor listed

below and ground.

LR Sensor circuit terminal 33

RR Sensor circuit terminal 19

If greater than the specified value, test the signal circuit for a short to voltage. If the
circuit tests normal, replace the wheel speed sensor.

4. Ignition OFF, test for infinite resistance between the low reference terminals of the

appropriate sensor listed below and ground.

LR Sensor circuit terminal 20

RR Sensor circuit terminal 31

If less than the specified value, test the low reference circuit for a short to ground. If

2008 Chevrolet Silverado 1500

2008 BRAKES Antilock Brake System - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

the circuit tests normal, test or replace the wheel speed sensor.

5. Test for infinite resistance between the following signal circuit terminals of the appropriate

sensor listed below and ground.

LR Sensor circuit terminal 33

RR Sensor circuit terminal 19

If less than the specified value, test the signal circuit for a short to ground. If the circuit
tests normal, test or replace the wheel speed sensor.

6. Ignition OFF, disconnect the harness connector at the appropriate WSS.

7. Test for less than 2 ohms between the appropriate low reference circuit terminals listed

below.

LR Sensor circuit terminals 20 at the EBCM harness connector, and terminal A at the
WSS harness connector

RR Sensor circuit terminals 31 at the EBCM harness connector, and terminal A at the
WSS harness connector

If greater than the specified value, test the low reference circuit for an open or high
resistance. If the circuit tests normal, test or replace the wheel speed sensor.

8. Test for less than 2 ohms between the appropriate signal circuit terminals listed below.

LR Sensor circuit terminals 33 at the EBCM harness connector, and terminal B at the
WSS harness connector

RR Sensor circuit terminals 19 at the EBCM harness connector, and terminal B at the
WSS harness connector

If greater than the specified value, test the signal circuit for an open or high resistance.
If the circuit tests normal, test or replace the wheel speed sensor.

9. If all circuits test normal, replace the EBCM.

Component Testing

1. Ignition OFF, disconnect the harness connector at the suspect wheel speed sensor.

2. Ignition On, test at the harness connector for 10-12 volts between the signal circuit terminal,

and low reference circuit terminal.

If not within the specified range, perform the Circuit/System Testing procedure.

3. Connect a jumper wire between the signal circuit terminal on the harness side, and to the

wheel speed sensor signal circuit terminal on the WSS.

4. Connect a DMM between the low reference terminal at the WSS, and to the low reference

terminal on the harness connector. Set up the DMM to measure mA using the DC scale.

5. Spin the wheel very slowly. Using the DMM MIN/MAX feature, test for 4-8 mA on the

2008 Chevrolet Silverado 1500

2008 BRAKES Antilock Brake System - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado

MIN capture, and 12-16 mA on the MAX capture. The sensor mA readings should toggle
from high to low with in the specified range.

If not within the specified range, replace the wheel speed sensor.

6. If all sensor circuits test normal, perform the Circuit/System Testing procedure.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Rear Wheel Speed Sensor Replacement

Control Module References for EBCM replacement, setup, and programming

DTC C0055 OR P0609 (WITH JF3 OR JH6)

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 Descriptors

DTC C0055 00

Rear Wheel Speed Sensor Circuit

DTC C0055 5A

Rear Wheel Speed Sensor Plausibility Failure

Diagnostic Fault Information

Circuit/System Description

The electronic control module (ECM) converts the data from the vehicle speed sensor to a 128K
pulses/mile signal. The electronic brake control module (EBCM) uses the vehicle speed signal
from the ECM in order to calculate the rear wheel speed.

Circuit

Short to

Ground

Open/High

Resistance

Short to

Voltage

Signal

Performance

Rear Wheel Speed Sensor Signal

C0055 00

C0055 00

C0055 00

C0055 5A

2008 Chevrolet Silverado 1500

2008 BRAKES Antilock Brake System - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado