Throttle Position Sensor (TPS)

A potentiometer provides the throttle position input signal to the MS41.1 Control Module. Throttle position and rate of throttle change are detected from the potentiometer. The operation of the sensor is the same as the throttle position sensors used on the Bosch engine management systems. The sensor receives its supply voltage from the control module. As the throttle is opened or closed, a varying voltage signal is produced that becomes the throttle position input to the control module.

The throttle position sensor operation is continuously monitored by the control module as part of the OBD II emission control requirements. The monitoring parameters include:

- Upper and lower limits for the input voltage
- Open circuits

If a malfunction occurs, relative throttle position is determined from the RPM and air mass sensor inputs (FAIL-SAFE). The fault is stored in memory and the Check Engine Lamp will illuminate when the OBD II requirements are satisfied.