DTC P0120: THROTTLE POSITION (TP) SENSOR Infiniti I30 I

1. Check Power Supply - Turn ignition off. Disconnect TP sensor harness connector. (Scheme 12) Turn ignition on. Measure voltage between TP sensor connector terminal No. 1 (Red wire) and ground. If voltage is about 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. Verify harness continuity between TP sensor connector terminal No. 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. Verify harness continuity between TP sensor connector terminal No. 2 (White wire) and ECM connector terminal No. 23. see scheme 4 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 (White wire) and No. 3 (Black wire). (Scheme 13) See THROTTLE POSITION SENSOR RESISTANCE table. If resistance is not as specified, adjust TP sensor. See «ADJUSTMENTS»(ref-18015) article. If resistance is still not as specified after adjustment, replace TP sensor.

THROTTLE POSITION SENSOR RESISTANCE (1)

Scheme 12

Scheme 13