Powertrain Controls - ECM/PCM

DTC 21/22 Throttle Position (TP) Sensor Circuit Low/Throttle Position (TP) Sensor Circuit High:

Throttle Position (TP) Sensor Circuit:

CIRCUIT DESCRIPTION
The Throttle Position (TP) sensor contains a resistor strip with one end connected to a 5 volt supply and the other to ground. The signal circuit is connected to a movable contact within the TP sensor. As the accelerator pedal is applied, the voltage signal wilt increase from approximately 0.5 volt to 4.5 volts.

DTC 21 WILL SET WHEN
^ Engine operating.
^ TP sensor signal voltage greater than 4.9 volts.
^ Conditions met for one second.

ACTION TAKEN (TCM will default to)
^ Maximum line pressure.
^ Use 35% throttle as default.
^ Inhibit 4th gear if in hot mode.

DTC 21 WILL CLEAR WHEN
Fault condition(s) are removed, and the ignition is cycled "OFF" then "ON."

DTC CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. This test checks for presence of 5 volts at the TP sensor.
2. Scan tool should display the 5 volt reference to the Transmission Control Module (TCM).

DIAGNOSTIC AIDS
^ The TP sensor voltage should increase smoothly as the accelerator pedal is applied.
^ If an intermittent is suspected check terminal tension at TP sensor and TCM. Also, use snapshot mode on scan tool to trigger on this DTC.