DTC P0120: Throttle Position (TP) Sensor: Procedure
- If malfunction "A" or "B" was duplicated, go to next step. If malfunction "C" was duplicated, adjust TP sensor. See ON-VEHICLE ADJUSTMENTS article. Check air intake duct and vacuum hoses for leaks or disconnection. Reconnect or repair as necessary. Go to next step.
- Turn ignition off. Loosen and retighten 2 engine ground bolts. See Figure. Disconnect TP sensor harness connector. See Fig 1. Turn ignition on. Measure voltage between TP sensor harness connector Pink/Black wire and ground. If voltage is about 5 volts, go to next step. If voltage is not about 5 volts, repair open or short between ECM and TP sensor.
- Turn ignition off. Check continuity of Black wire between TP sensor harness connector and ground. If continuity exists, go to next step. If continuity does not exist, repair open in Black wire. See appropriate wiring diagram in WIRING DIAGRAMS article.
- Disconnect ECM harness connector. See Figure. Check continuity of White wire between ECM harness connector terminal No. 23 and TP sensor harness connector. See Figure. If continuity exists, go to next step. If continuity does not exist, repair open in White wire between ECM and TP sensor.
- Measure resistance between TP sensor terminals No. 2 and 3 with throttle in specified position. See THROTTLE POSITION (TP) SENSOR RESISTANCE table. See Fig 1. If resistance is as specified, go to next step. If resistance is not as specified, replace TP sensor.
- Check MAF sensor. See DTC P0100: MASS AIRFLOW (MAF) SENSOR . Replace, if necessary. If MAF sensor is okay, check CMP sensor. See DTC P0340: CAMSHAFT POSITION (CMP) SENSOR . Replace, if necessary. If CMP sensor is okay, go to next step.
- Check fuel injectors and circuits. See FUEL CONTROL in SYSTEM & COMPONENT TESTING article. Repair or replace as necessary. If fuel injectors and circuits are okay, go to next step.
- Check shield circuit for continuity to ground. Shield is connected to ground through connector F-21 (Blue, 12-pin joint connector located near ECM). See appropriate wiring diagram in WIRING DIAGRAMS article. If continuity does not exist, repair open circuit. If continuity exists, no problem is currently indicated. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.
THROTTLE POSITION SENSOR RESISTANCE
| Throttle Position | Ohms @ 77°F (25°C) |
|---|---|
| Fully Closed | About 500 |
| Partially Open | 500-4000 |
| Fully Open | About 4000 |