Conditions

Throttle Position Sensor







Fault symptoms
CHECK ENGINE lamp on. High idling speed. A/C compressor not working.

Conditions
P0121:
- No diagnostic trouble codes generated for the fuel system.
- >200 sec. since start of closed loop.
- Vehicle speed >20 km/h.
- Engine speed 1500-2500 rpm.
- Engine coolant temperature >70C (158F).
- Intake pressure 38-80 kPa.
- AC not active
- Intake pressure differs more than 40 kPa from that calculated on throttle position and intake temperature.

P0122 Engine running: <0.2 V for 5 sec.
P0123 Engine running: >4.96 V for 5 sec.

Diagnostic help
The function of the throttle position sensor can be read with the diagnostic tool.
- Turn the ignition to ON and then back to OFF.
- Connect the diagnostic tool.
- Select "READ FUNCTIONS".
- Select "THROTTLE POSITION".

The diagnostic tool should show the current throttle position if the throttle position sensor is in working order, 10-90% (0.5 - 4.5 V) from released to fully depressed accelerator pedal.

Checking the wiring harness. Intermittent faults may occur in connection with short circuits and open circuits. Jiggle the wiring harness at several points and in several directions to locate any problems in the wiring, including intermediate connectors. Observe the multimeter, scan tool or test lamp during the check.