Fail Safe Results
If the pump motor current exceeded 100 Amps for 10 or more seconds, power assist will cease. The STEERING light will come on and the duty ratio will be reduced to 0 percent. However, full manual control will allow the vehicle to be safely driven.
If the vehicle voltage drops below 9 volts, there will be partial power assist. The STEERING light will come on and the duty ratio will be gradually reduced. Should the voltage recover, the duty ratio will return to normal and the steering light will go off.
If the engine stalls, the STEERING light will come on and the duty ratio will be gradually reduced. This allows power assist for several seconds. Once the engine is restarted however, the STEERING light goes off and the power assist returns as needed.
Should there be a loss of the speed sensor signal (Above 15 MPH), the STEERING light will come on and the duty ratio will be maintained at the previously set level.
Note: Prior to any servicing or fault diagnosis, confirm that the vehicle has had MPS controller set PIN 31186GA070 installed. For additional details refer to Campaign Bulletin #WZM-48.
For vehicles which have had this replacement procedure performed, refer to MSA5T9212A XT6 Electronic Controlled Motor Drive Power Steering Service Manual Supplement and the appropriate model year Service Manual, Section 4-3 for D-Check and fault diagnosis procedures.