Troubleshooting
DTC P0120 THROTTLE/PEDAL POSITION SENSOR/SWITCH "A" CIRCUIT MALFUNCTIONCIRCUIT DESCRIPTION
DTC Detecting Condition:
The throttle position sensor is mounted in the throttle body and detects the throttle valve opening angle.
When the throttle valve is fully closed, a voltage of approximately 0.3 - 1.0 V is applied to terminal VTA of the ECM. The voltage applied to the terminals VTA of the ECM increases in proportion to the opening angle of the throttle valve and becomes approximately 3.2 - 4.9 V when the throttle valve is fully opened. The ECM judges the vehicle driving conditions from these signals input from terminal VTA, uses it as one of the conditions for deciding the air-fuel ratio correction, power increase correction and fuel-cut control etc.
HINT: After confirming DTC P0120, use the hand-held tester or OBD II scan tool to confirm the throttle valve opening percentage.
Wiring Diagram:
Step 1 - 3:
Step 4 - 5:
Step 6 - 7:
INSPECTION PROCEDURE
HINT:
- Read freed frame data using hand-held tester or OBD II scan tool. Because freeze frame records the engine conditions when the malfunction is detected, when troubleshooting it is useful for determining whether the vehicle was running or stopped, the engine warmed up or not, the air-fuel ratio lean or rich, etc. at the time of the malfunction.
- If DTC P0100 (Mass Air Flow Meter Circuit Malfunction), P0110 (Intake Air Temperature Circuit Malfunction), P0115 (Engine Coolant Temperature Circuit Malfunction), P0120 (Throttle/Pedal Position Sensor/Switch "A" Malfunction) are output simultaneously, E1, E2 (Sensor Ground system) may be open.
CHECK FOR INTERMITTENT PROBLEMS
Hand-held tester only:
By putting the vehicle's ECM in the check mode, 1 trip detection logic is possible instead of 2 trip detection logic and the sensitivity to detect open circuits is increased. This makes it easier to detect intermittent problems.
1. Clear the DTC.
2. Set the check mode.
3. Perform a simulation test.
4. Check the connector and terminal.
5. Handle the connector.