Cherokee 2WD L4-150 2.5L VIN P MFI (1991)
Throttle Position Sensor: Description and Operation
Throttle Position Sensor (TPS)
This sensor is used to send input signals to the Single Board Engine Controller II (SBEC II) to indicate the current angle of the throttle blade. This
sensor is a variable resistor that has a 5 volt reference signal applied to it by the SBEC II. The Throttle Position Sensor (TPS) sends signals back to the
SBEC II in the range of approximately 1 to 4 volts, depending upon the throttle shaft angle. The SBEC uses these input voltages to determine the current
position of the throttle.
An input voltage of approximately 1 volt indicates a minimum throttle opening or idle condition. An input voltage of approximately 4 volts would
indicate a maximum throttle opening or wide open throttle condition.
The SBEC II uses the voltage signals from the TPS and other input sensors to determine the proper air/fuel mixture and ignition timing for certain
operating conditions. Some of these operating conditions are: acceleration, deceleration, idle, and wide open throttle.
