Standard Models (Non-Alternative Fuels)

CIRCUIT DESCRIPTION
The Throttle Position (TP) sensor is a potentiometer. The powertrain control module (PCM) supplies the TP sensor a reference voltage, a signal, and ground circuits. When the throttle is depressed, the TP sensor signal rises to near the reference voltage. When the throttle is released, the TP sensor signal decreases from the reference voltage. The control module monitors the TP sensor signal circuit voltage in order to determine the throttle blade angle, or opening.

This Diagnostic Trouble Code (DTC) is designed to detect a TP sensor signal voltage higher than the possible operating range of a normally functioning TP sensor.

CONDITIONS FOR RUNNING THE DTC
The engine is running.

CONDITIONS FOR SETTING THE DTC
The TP sensor signal voltage is more than 4.7 volts for 1 second or more.

ACTION TAKEN WHEN THE DTC SETS
^ The control module illuminates the Malfunction Indicator Lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
^ The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
^ A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
^ A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
^ Use a scan tool in order to clear the MIL and the DTC.

DIAGNOSTIC AIDS
The scan tool reads the throttle position in volts. The scan tool should read between 0.45-0.85 volt with the throttle closed and the ignition switch turned ON or at idle. The voltage should increase at a steady rate as the throttle is moved toward the Wide Open Throttle (WOT) position.

The scan tool will read the throttle angle percentage. 0 percent equals closed throttle. 100 percent equals Wide Open Throttle (WOT).

Scan the TP sensor while depressing the accelerator pedal with the engine turned OFF and the ignition turned ON. The display should vary from less than 1.25 volts (1,250 mV) with the throttle closed to more than 4.5 volts (4,500 mV) when the throttle is held at the WOT position.

This DTC will result if the TP ground circuit is open or the TP sensor signal circuit is shorted to voltage. Refer to Symptoms - Computers and Control Systems. Standard Model (Non-Alternative Fuels)

An intermittent may be caused by any of the following conditions:
^ A poor connection
^ Rubbed through wire insulation
^ A broken wire inside the insulation

Thoroughly inspect any circuitry that is suspected of causing the intermittent complaint. Refer to Testing for Intermittent and Poor Connections in Diagrams.

If a repair is necessary, refer to Wiring Repairs or Connector Repairs in Diagrams.

TEST DESCRIPTION

Steps 1-11:

Steps 12-16:

The numbers below refer to the step numbers on the diagnostic table.
2. if the TP signal measures more than 4.8 volts, then the condition exists.
3. With the TP sensor disconnected, and if the PCM and the wiring are okay, the TP signal should go below 0.25 volt. This test could set a DTC P0122.