Grand Prix V6-3.1L VIN J (2000)
Throttle Position Sensor: Description and Operation
The nonadjustable TP sensor is mounted on the side of the throttle body opposite the throttle lever. It senses the throttle valve angle and relays that
information to the PCM. Knowledge of the throttle angle is needed by the PCM to generate the required injector control signals (pulse). For further
information, Refer to In formation Sensors/Switches Description.
The Throttle Position (TP) sensor is a potentiometer connected to the throttle shaft on the throttle body. By monitoring the voltage on the signal line, the
PCM calculates throttle position. As the throttle valve angle is changed (accelerator pedal moved), the TP sensor signal also changes. At a closed throttle
position, the output of the TP sensor is low. As the throttle valve opens, the output increases so that at Wide Open Throttle (WOT), the output voltage
should be above 4.0volts.
The PCM calculates fuel delivery based on throttle valve angle (driver demand). A broken or loose TP sensor may cause intermittent bursts of fuel from
an injector and unstable idle because the PCM thinks the throttle is moving. A hard failure in the TP sensor 5.0 volt reference or signal circuits should
set either a DTC P0122 Throttle Position (TP) Sensor Circuit Low Voltage DTC P0123 Throttle Position (TP) Sensor Circuit High Voltage. A hard
failure with the TP Sensor ground circuit may set DTCs DTC P0107 Manifold Absolute Pressure (MAP) Sensor Circuit Low Voltage, DTC P0112
Intake Air Temperature (IAT) Sensor Circuit Low Voltage, DTC P0123 Throttle Position (TP) Sensor Circuit High Voltage, or DTC P0117 Engine
Coolant Temperature (ECT) Sensor Circuit Low Voltage. Once a DTC is set, the PCM will use an artificial default value based on engine RPM, engine
load and mass air flow for throttle position and some vehicle performance will return. A high idle may result when either DTC P0122 Throttle Position
(TP) Sensor Circuit Low Voltage, or DTC P0123 Throttle Position (TP) Sensor Circuit High Voltage is set.
