Buick Regal: Power Steering Assist Motor Replacement

Removal Procedure

CAUTION: Electrostatic discharge (ESD) can damage many solid-state electrical components. ESD susceptible components may or may not be labeled with the ESD symbol. Handle all electrical components carefully. Use the following precautions in order to avoid ESD damage:

• Touch a metal ground point in order to remove your body's static charge before servicing any electronic component; especially after sliding across the vehicle seat.
• Do not touch exposed terminals. Terminals may connect to circuits susceptible the ESD damage.
• Do not allow tools to contact exposed terminals when servicing connectors.
• Do not remove components from their protective packaging until required to do so.
• Avoid the following actions unless required by the diagnostic procedure:
  • Jumpering or grounding of the components or connectors.
  • Connecting test equipment probes to components or connectors.
    Connect the ground lead first when using test probes.
• Ground the protective packaging of any component before opening.

  Do not rest solid-state components on metal workbenches, or on top of TVs, radios, or other electrical devices.

CAUTION: During removal and installation, all EPS components including mechanical and/or electrical is extremely susceptible to damage. Dropping or prying on any EPS component may cause internal damage. If damage occurs or a part is dropped, the EPS component must be replaced.

CAUTION: Care must be taken during removal and installation of the Electronic Power Steering (EPS) components to not hit or break the EPS motor/controller module or module harness connectors. If the EPS motor/ controller module or module connectors are damaged, the complete component must be replaced.

1. Perform the strategy based diagnosis. Performing the strategy based diagnostics includes reviewing related bulletins, preliminary information and diagnostics.

NOTE:

• The power steering control module is part of the power steering assist motor.
• If communication with the OLD power steering control module cannot be established, then replace the entire steering gear as an assembly. Do NOT proceed with replacement of just the power steering assist motor.

2. Capture the key cycle count from the OLD steering gear control module. If the key cycle count from the OLD steering gear control module is NOT captured, it will NOT be possible to flash the NEW steering gear control module.

3. Steering Gear - Remove.

4.

CAUTION: Do NOT pry on the Power Steering Assist Motor electrical connector.
Prying on the Power Steering Assist Motor electrical connector could crack the Power Steering Assist Motor housing. If the Power Steering Assist Motor housing is cracked, the motor assembly must be replaced.

Remove the connector position assurance lock (1) from the electrical connector(2).

5. Discard the connector position assurance lock if damaged during removal.

6.

Depress connector tab (1) and disconnect the electrical connector (2) from the power steering assist motor(3).

7.

Power Steering Assist Motor Bolt(1) - Remove and DISCARD[2x].

8. Power Steering Assist Motor(2) - Remove.

9.

Remove the Steering Gear Drive Coupling(1) - Remove and DISCARD.

10. Power Steering Assist Motor Seal(2) - Remove and DISCARD.

NOTE:

• Inspection of the steering gear motor shaft and the inside of the steering gear housing is REQUIRED to ensure that there are NO signs of water intrusion or corrosion which MAY cause premature motor failure.
• If signs of water intrusion or corrosion ARE present then the steering gear MUST be replaced.

11. Inspect the steering gear motor shaft and inside of the steering gear housing for signs of water intrusion or corrosion. If no signs of water intrusion or corrosion are present proceed to the next step.

If signs of water intrusion or corrosion are present then replace the steering gear.

Installation Procedure

1.

Power Steering Assist Motor Seal(2) - Install NEW.

2. After the power steering assist motor seal (2) is placed on the power steering assist motor, apply a thin layer of grease to the seal.

3. Steering Gear Drive Coupling(1) - Install NEW.

4.

NOTE: The steering gear drive coupling and assist motor armature should be aligned with the gear inside of the steering gear housing to aid in installation, otherwise interference MAY occur.

Position the power steering assist motor (2) with the steering gear housing and start the power steering assist NEW motor bolt(1).[2x].

5. With the power steering assist motor bolt (1) started, completely install the power steering assist motor (2)to the steering gear housing.

CAUTION: Refer to Fastener Caution.

6. Power steering assist motor bolt (1) Install NEW and tighten[2x] 21 N.m (15 lb ft).

7.

Connect the electrical connector (1) to the power steering assist motor.

8. Verify connector (1) is fully seated by lightly pulling on the connector.

9.

NOTE: If the connector position assurance lock (1) was damaged during removal, discard it and skip step 8.

Install the connector position assurance lock (1) into the electrical connector (2) until fully seated.

10. Steering Gear - Install.

11. Transfer the key cycle count from the OLD steering gear control module to the NEW steering gear control module.

POWER STEERING CONTROL MODULE CALIBRATION

Steering Angle Sensor Centering and Software Endstop Learning

WARNING: An inaccurate or not centered steering angle sensor could limit the operation of the electric power steering and may result in personal injury.

Centering of the steering angle sensor and software endstop learning might be required after certain service procedures are performed. Some of these procedures are as follows:

• Steering angle sensor replacement
• Steering gear replacement
• Power steering assist motor replacement
• Steering column replacement
• Steering linkage inner tie rod replacement
• Steering linkage outer tie rod replacement

NOTE: It is necessary to perform the steering angle sensor centering BEFORE the software endstop learning.

Steering Angle Sensor Centering

For electronic power steering equipped vehicles WITH electronic stability control program and EXTERNAL Steering Angle Sensor, refer to Steering Wheel Angle Sensor Centering.

The centering procedure of the internal steering angle sensor (w/o electronic stability program) can be completed with the following steps: Conditions: Front axle measured and set, engine running, vehicle speed 0 km/h (0 MPH), internal steering angle sensor is activated.

1. Using the steering wheel, align the front wheels in the center forward position.

2. Using a scan tool, perform the Configuration/Reset Functions, Steering Wheel Angle Sensor Centering procedure.

3. Steer from the center position slowly 90º to the left.

4. Steer slowly back to the center position and then slowly 90º to the right.

5. Steer slowly back to the center position.

6. Perform the steering movements again.

7. Centering procedure is completed.

Software Endstop Learning

The software endstop learning procedure can be completed with the following steps:

Conditions: Front axle measured and set, vehicle speed 0 km/h (0 MPH), internal steering angle sensor is calibrated or external steering angle sensor sends a valid CAN signal.

1. Using a scan tool, perform the Configuration/Reset Functions, Power Steering Softstops Reset procedure and follow the on-screen instructions.

2. Using a scan tool, perform the Configuration/Reset Functions, Power Steering Softstops Learn procedure and follow the on-screen instructions.

3. Software endstop learning procedure is completed.

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