Cruze

Variable Effort Steering Malfunction

The electronic brake control module controls the variable effort steering actuator on the steering gear. As speed increases the electronic brake control module commands the amperage to the actuator to a maximum of 1 A, this closes the orifice and restricts fluid flow for a firm steering effort. At low speeds and parking lot manoeuvres the orifice is normally open allowing maximum fluid flow for an easy steering effort.

Schematic Reference

Power Steering Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Variable Effort Steering System Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

Note: It is recommended that Component Testing is performed before Circuit/System Testing when diagnosing the variable power steering solenoid valve.

1. Ignition OFF, disconnect the harness connector at the M72 Variable Power Steering Solenoid Valve.
2. Ignition ON, test for less than 0.3 V between the control terminals listed below and ground.

•	M72 Variable Power Steering Solenoid Valve, terminal A

•	M72 Variable Power Steering Solenoid Valve, terminal B

⇒	If greater than the specified value, test the control circuits for a short to voltage. If the circuit tests normal, replace the K17 Electronic Brake Control Module (EBCM).

3. Ignition OFF, disconnect the negative terminal of the C1 Battery.
4. Test for infinite resistance between the control circuit terminals listed below and B+.

•	M72 Variable Power Steering Solenoid Valve, terminal A

•	M72 Variable Power Steering Solenoid Valve, terminal B

⇒	If not within the specified range, test the control circuit for a short to ground. If the circuit tests normal, replace the K17 Electronic Brake Control Module (EBCM).

5. Disconnect the harness connector at the K17 Electronic Brake Control Module (EBCM). Test for less than 5 Ω between the control circuit terminals listed below:

•	M72 Variable Power Steering Solenoid Valve, terminal A and K17 Electronic Brake Control Module (EBCM), terminal 3

•	M72 Variable Power Steering Solenoid Valve, terminal B and K17 Electronic Brake Control Module (EBCM), terminal 31

⇒	If greater than the specified value, test the control circuit for an open/high resistance.

6. If all circuits test normal, test or replace the K17 Electronic Brake Control Module (EBCM).

Static Test

1. Ignition OFF, disconnect the harness connector at the M72 Variable Power Steering Solenoid Valve.
2. Test for 5-10 Ω between control terminal A and control terminal B.

⇒	If not the specified range, replace the M72 Variable Power Steering Solenoid Valve.

3. Test for infinite resistance between each terminal and the M72 Variable Power Steering Solenoid Valve housing case.

⇒	If not the specified value, replace the M72 Variable Power Steering Solenoid Valve.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.