Troubleshooting
DTC P0120 Throttle/Pedal position Sensor/Switch "A" CircuitCIRCUIT 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 0.7 V is applied to terminal VTA of the ECM. The voltage applied to terminals VTA of the ECM increases in proportion to the opening angle of the throttle valve and becomes approximately 3.5 - 4.5 V when the throttle valve is fully opened. The ECM judges the vehicle driving conditions from these signals input from terminals VTA and uses them as one of the conditions for deciding the air-fuel ratio correction, power increase correction and fuel-cut control etc. DTC No.
HINT: After confirming DTC P0120, use the OBD II scan tool or hand-held tester to confirm the throttle valve opening percentage and closed throttle position switch condition.
MONITOR DESCRIPTION
Monitor Strategy:
Typical Enabling Conditions:
Typical Malfunction Thresholds:
Component Operating Range:
The ECM uses the throttle position sensor to monitor the throttle valve opening angle.
VTA have a specific voltage operating range.
If VTA is out of the normal operating range, the ECM interprets this as a fault and will set a DTC.
Wiring Diagram:
Step 1 - 2:
Step 3 - 4:
Step 5:
INSPECTION PROCEDURE
HINT:
- If DTCs P0110, P0115 and P0120 are output simultaneously, E2 (sensor ground) may be open.
- Read freeze frame data using OBD II scan tool or hand-held tester. 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 was warmed up or not, the air-fuel ratio was lean or rich, etc. at the time of the malfunction.
CHECK FOR INTERMITTENT PROBLEMS
Hand-held tester only:
Inspect the vehicle's ECM using check mode. Intermittent problems are easier to detect when the ECM is in check mode with hand-held tester. In check mode, the ECM uses 1 trip detection logic, which has a higher sensitivity to malfunctions than normal mode (default), which uses 2 trip detection logic.
a. Clear the DTCs.
b. Set the check mode.
c. Perform a simulation test.
d. Check the connector and terminal.
e. Wiggle the harness and connector.