Speed Proportional Power Assist Steering (1997 and Prior)

The Speed Proportional Power Assist Steering System is used to enhance steering feel. This is most noticeable from zero mph to approximately 60 mph.
To verify operation of speed proportional steering based on subjective feel using the the DRB Scan Tool, use the "SPD PROP STEER" test found under "Miscellaneous". Before performing this test, certain criteria must be met as listed below. Any one of these criteria not met will result in the test being discontinued.
1. Place the gear select lever in Park.
2. Apply the brake.
3. Start the engine.

Once these three things have been done, the SPD PROP STEER test may be performed. When the SPD PROP STEER test in running, the speedometer will display approximately 60 mph and the steering wheel will require more effort to turn. Turn the steering wheel back and forth while alternately depressing and releasing the brake pedal. The steering wheel should require noticeably less effort to turn while the brake
pedal is released.

If you find that the speed proportional steering is not functioning properly, check for the following possible cause(s):
- Open or short on the vehicle speed sensor circuit
- Open speed sensor ground circuit
- Open or short on the fused ignition switch output circuit
- Pigtail; disconnected between SPS Module and solenoid control valve
- Internal short in the SPS Module
- Internal short in the TCM (only if no speedometer operation)

NOTE: For 1998 MY the Speed Pro Steering System is controlled by the BCM. Refer to Computers and Control Systems.