CHECK WIRE HARNESS (THROTTLE POSITION SENSOR - ECM)
CHECK ECM TERMINAL VOLTAGE (VC TERMINAL)
REPLACE DIESEL THROTTLE BODY ASSEMBLY
CHECK WHETHER DTC OUTPUT RECURS
DTC P0120 Throttle / Pedal Position Sensor / Switch "A" Circuit |
DTC P0122 Throttle / Pedal Position Sensor / Switch "A" Circuit Low Input |
DTC P0123 Throttle / Pedal Position Sensor / Switch "A" Circuit High Input |
DESCRIPTION
The throttle position sensor is mounted on the diesel throttle body and detects the opening angle of the throttle valve. This sensor is an electronic sensor and uses Hall-effect elements.The ECM determines the vehicle's driving conditions from the signals input to its VLU terminal. The data is one of the inputs used for EGR control, etc.

DTC No. | DTC Detection Condition | Trouble Area |
- | Condition of DTC P0120, P0122, or P0123 continues for 0.5 seconds (open or short in throttle position sensor circuit) | - |
P0120 | Throttle position sensor output (VLU) varies beyond normal operating range (less than 0.2 V or more than 4.8 V) (1 trip detection logic) |
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P0122 | Throttle position sensor output (VLU) is less than 0.2 V (1 trip detection logic) |
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P0123 | Throttle position sensor output (VLU) is more than 4.8 V (1 trip detection logic) |
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MONITOR DESCRIPTION
When the output voltage of the throttle position sensor deviates from the normal operating range (between 0.2 V and 4.8 V) for more than 3 seconds, the ECM interprets this as a malfunction of the sensor circuit and illuminates the MIL.
WIRING DIAGRAM

INSPECTION PROCEDURE
- ПРИМЕЧАНИЕ:
- After replacing the ECM, the new ECM needs registration (see page RAV4_ACA30 RM000000TJ4007X.html) and initialization (see page RAV4_ACA30 RM000000TIN007X.html).
- УКАЗАНИЕ:
- If DTCs relating to different systems are output, and they share terminal E2 as their ground, check this ground circuit first.
1.CHECK WIRE HARNESS (THROTTLE POSITION SENSOR - ECM) |
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Disconnect the B55 throttle position sensor connector.
Disconnect the B32 ECM connector.
Measure the resistance of the wire harness side connectors.
- Standard resistance:
Tester Connection Specified Condition B55-1 (VC) - B32-73 (VCVL) Below 1 Ω B55-3 (VTA) - B32-119 (VLU) Below 1 Ω B55-2 (E2) - B32-96 (EVLU) Below 1 Ω B55-1 (VC) or B32-73 (VCVL) - Body ground 10 kΩ or higher B55-3 (VTA) or B32-119 (VLU) - Body ground 10 kΩ or higher B55-2 (E2) or B32-96 (EVLU) - Body ground 10 kΩ or higher
Reconnect the throttle position sensor connector.
Reconnect the ECM connector.
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OK | |
2.CHECK ECM TERMINAL VOLTAGE (VC TERMINAL) |
Disconnect the B55 throttle position sensor connector.
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Turn the ignition switch on (IG).
Measure the voltage of the wire harness side connector.
- Standard voltage:
Tester Connection Specified Condition B55-1 (VC) - B55-2 (E2) 4.5 to 5.5 V
Reconnect the throttle position sensor connector.
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OK | |
3.REPLACE DIESEL THROTTLE BODY ASSEMBLY |
Replace the diesel throttle body assembly.
NEXT | |
4.CHECK WHETHER DTC OUTPUT RECURS |
Connect the intelligent tester to the DLC3.
Turn the ignition switch on (IG) and the tester ON.
Clear the DTCs (see page RAV4_ACA30 RM000000PDK01FX.html).
Start the engine.
Let the engine idle for 60 seconds.
Repeat quick engine revving to 2,500 rpm for 30 seconds.
Read the DTCs.
- Result:
Display (DTC Output) Proceed to P0120, P0122 and/or P0123 A No output B
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A | ||
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