DTC P0120 - THROTTLE POSITION (TP) SENSOR Nissan 240SX S14

1. Check Power Supply Turn ignition off. Disconnect TP sensor harness connector. (Scheme 18) Turn ignition on. Measure voltage between TP sensor connector terminal "1" (Green/Red wire) and ground. If voltage is about 5 volts, go to next step. If voltage is not about 5 volts, repair harness or connectors as necessary.
2. Check Ground Circuit Turn ignition off. Check harness continuity between TP sensor connector terminal "3" (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. Check harness continuity between ECM connector terminal No. 23 and TP sensor connector terminal "2" (White wire). (Scheme 19) If continuity is present, go to next step. If continuity is not present, repair harness or connectors as necessary.
4. Check Component Inspect TP sensor. See the «SYSTEM/COMPONENT TESTS»(ref-17826) article. Replace TP sensor if necessary and perform «FINAL CHECK»(ref-17825-S20538276422000122900000). If sensor is okay, check ECM pin terminals and/or wiring harness connector.

Scheme 18

Scheme 19