Chevrolet Silverado / GMC Sierra. Service manual — part 707

LF Sensor circuit terminals 34 at the EBCM harness connector, and terminal 2 at the
WSS harness connector

RF Sensor circuit terminals 18 at the EBCM harness connector, and terminal 2 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.

Circuit/System Testing

With JH6/JH7

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.

LF Sensor circuit terminal 16

RF Sensor circuit terminal 27

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

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

below and ground.

LF Sensor circuit terminal 15

RF Sensor circuit terminal 26

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

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

appropriate sensor listed below and ground.

LF Sensor circuit terminal 16

RF Sensor circuit terminal 27

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

2008 Chevrolet Silverado 1500

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

LF Sensor circuit terminal 15

RF Sensor circuit terminal 26

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

below.

LF Sensor circuit terminals 16 at the EBCM harness connector, and terminal A at the
WSS harness connector

RF Sensor circuit terminals 27 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.

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

LF Sensor circuit terminals 15 at the EBCM harness connector, and terminal B at the
WSS harness connector

RF Sensor circuit terminals 26 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.

8. 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

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.

2008 Chevrolet Silverado 1500

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

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Front Wheel Speed Sensor Replacement (JD9, JF3, JF7) or Front Wheel Speed
Sensor Replacement (JH6, JH7)

Control Module References for EBCM replacement, setup, and programming

DTC C0045 OR C0050 (WITH JL4)

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 C0045 00

Left Rear Wheel Speed Sensor Circuit

DTC C0045 5A

Left Rear Wheel Speed Sensor Circuit Erratic Signal

DTC C0050 00

Right Rear Wheel Speed Sensor Circuit

DTC C0050 5A

Right Rear Wheel Speed Sensor Circuit Erratic Signal

Diagnostic Fault Information

Circuit

Short to

Ground

Open/High

Resistance

Short to

Voltage

Signal

Performance

Left Rear Sensor Signal Circuit

C0045 00

C0045 00

C0045 00

C0045 5A

Left Rear Sensor 12 volt
Reference Circuit

-

C0045 00

-

C0045 5A

2008 Chevrolet Silverado 1500

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

Circuit/System Description

The wheel speed sensor receives ignition voltage from the electronic brake control module
(EBCM) and provides a DC square wave signal back to the module. As the wheel spins, the
EBCM uses the frequency of the square wave signal to calculate the wheel speed.

Conditions for Running the DTC

C0045 00 or C0050 00

The ignition is ON.

Ignition voltage is greater than 9.5 volts.

C0045 5A or C0050 5A

The ignition is ON.

Ignition voltage is greater than 9 volts.

The brake pedal is not pressed.

A DTC is not set for the other wheel speed circuit on the same axle.

Conditions for Setting the DTC

An erratic signal output of the wheel speed sensor is detected.

A short to voltage, open or ground is detected on the wheel speed sensor signal circuit.

A open or short to ground in the wheel speed sensor circuit supply voltage.

A missing wheel speed sensor signal

Action Taken When the DTC Sets

The amber ABS indicator turns ON.

The Traction Control indicator turns ON.

The driver information center (DIC) displays the warning message.

Conditions for Clearing the DTC

The condition for setting the DTC is no longer present.

Right Rear Sensor Signal Circuit

C0050 00

C0050 00

C0050 00

C0050 5A

Right Rear Sensor 12 volt
Reference Circuit

-

C0050 00

-

C0050 5A

2008 Chevrolet Silverado 1500

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