Note. If DTCs P0110, P0115, P0120 and P0450 are output together, check circuit E2 (Blue/Black wire) between terminal No. 9 at ECM harness connector E6 and splice I11. Repair as necessary. See appropriate wiring diagram in WIRING DIAGRAMS article.
Circuit Description
TP sensor is located on throttle body and has a variable resistor integral to TP sensor. TP sensor monitors throttle opening. ECM determines vehicle driving condition and adjusts air/fuel mixture accordingly. DTC is set when ECM detects voltage is out of range on VTA circuit. Possible causes are
- TP sensor circuit is open or shorted.
- Defective TP sensor.
- Defective ECM.
Diagnostic Aids
After confirming DTC P0120, use scan tool to access CURRENT DATA to confirm throttle valve opening percentage with throttle open and closed. If percentage displayed on scan tool is always zero percent, VCC circuit may be open, or VTA circuit may be open or shorted. If percentage displayed on scan tool is always 100 percent, E2 circuit may be open. Using scan tool, read freeze frame data. Freeze frame records engine conditions when malfunction is detected.