DTC P0121 - TP SENSOR SYSTEM PERFORMANCE Oldsmobile Cutlass VI

Note. For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

The Powertrain Control Module (PCM) supplies a 5-volt reference signal and a ground circuit to Throttle Position (TP) sensor, and a signal circuit to monitor changes in throttle angle. TP sensor signal voltage should be about .5 volt at idle and 4.0 volts or greater at wide open throttle.

Conditions for setting DTC are as follows

1. No active TP sensor or MAP sensor DTC.
2. Engine is running.
3. MAP sensor reading is less than 55 kPa.
4. Predicted throttle angle is not close to actual throttle angle.
5. TP sensor angle is greater than 60 percent at 1600 RPM.