DTC P0120: Throttle Position (TP) Sensor

NOTE: For testing of tandem throttle position sensor, start at DTC P1125 - TANDEM THROTTLE POSITION SENSOR .

1. Check Power Supply  - Turn ignition off and disconnect TPS harness connector. See Fig 1. Turn ignition on. Measure voltage between TPS connector termina l No. 4 (Brown/White wire) and ground. If voltage is approximately 5 volts, go to next step. If voltage is not as specified, repair harness or connectors as necessary.
2. Check Ground Circuit  - Turn ignition off. Loosen and retighten engine ground bolts. See Figure. Verify harness continuity between TPS connector terminal No. 2 (Black wire) and engine ground. If continuity is present, go to next step. If continuity is not present, repair harness or connectors as necessary.
3. Check Input Signal Circuit  - Disconnect ECM harness connector. Verify harness continuity between TPS connector terminal No. 1 (Green wire) and ECM connector terminal No. 23. If continuity is present, go to next step. If continuity is not present, repair harness or connectors as necessary.
4. Check Component  - Leave TP sensor disconnected. While opening and closing throttle, check resistance across TP sensor connector terminal No. 2 and No. 3. See Fig 1. See THROTTLE POSITION SENSOR RESISTANCE table. If resistance is not as specified, adjust TP sensor. See ADJUSTMENTS article. If resistance is still not as specified after adjustment, replace TP sensor.

THROTTLE POSITION SENSOR RESISTANCE ⁽¹⁾

Throttle Position	Ohms
Fully Closed	About 600
Partially Opened	600-4000
Fully Open	About 5000
(1) Ensure resistance changes when opening and closing throttle.

Fig 1: Testing Throttle Position (TP) Sensor

Courtesy of NISSAN MOTOR CO., U.S.A.