GM Service Manual Online
For 1990-2009 cars only
Actual Motor Current: The scan tool displays 0.0 amps to 58.0 amps. The actual amount of current the power steering control module (PSCM) is commanding to the electric power steering (EPS) motor.

Battery Voltage: The scan tool displays 8-17 volts. The level of battery voltage available at the PSCM.

Desired Motor Current: The scan tool displays 0.0 amps to 58.0 amps. The amount of current the PSCM is attempting to command to the EPS motor.

Ignition Voltage: The scan tool displays 0-17 volts. The level of ignition voltage available at the PSCM.

Limiting Motor Current: The scan tool displays up to 65 amps. The amount of current last commanded to the EPS motor before the system went into overload protection mode. 65 amps indicates that an overload protection incident has not occurred.

Motor Voltage +: The scan tool displays 7.0-14.0 volts. The amount of voltage being supplied to the EPS motor while turning right.

Motor Voltage -: The scan tool displays 7.0-14.0 volts. The amount of voltage being supplied to the EPS motor while turning left.

Torque Sensor Amplified: The PSCM takes the detection coil voltage and multiplies it. This amplified signal voltage is used by the PSCM to compensate for lag in mechanical steering components.

Torque Sensor Main: The scan tool displays -17.2 N·m to 17.2 N·m (12.6 lb ft). The amount of torque being applied to the steering column shaft when turning the steering wheel. This signal voltage is from the detection coil of the torque sensor which is then converted to N·m by the PSCM. A negative value indicates a left turn, a positive value indicates a right turn.

Torque Sensor Sub: The scan tool displays -17.2 N·m to 17.2N·m (12.6 lb ft). this signal voltage is from the compensation coil of the torque sensor which is then converted to N·m by the PSCM. The Torque Sensor Main and Torque Sensor Sub data parameters should behave the same as each other.

Tuning Profile: The scan tool displays 1-8, the number of the calibration that the PSCM is using. If the PSCM is replaced, the new PSCM must be setup with the proper steering tuning profile calibration using the service programming system.

Vehicle Speed: The scan tool displays 0-255 km/h (0-156 mph). The actual speed of the vehicle.