Lexus IS250 IS220d GSE20 ALE20 2AD-FHV ENGINE CONTROL SYSTEM
CHECK HARNESS AND CONNECTOR (THROTTLE POSITION SENSOR - ECM)
CHECK TERMINAL VOLTAGE (VC TERMINAL OF THROTTLE POSITION SENSOR)
REPLACE DIESEL THROTTLE BODY ASSEMBLY
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) flutters up and down beyond normal operating range (less than 0.2 V or more than 4.8 V) (1 trip detection logic) |
Open or short in throttle valve position sensor circuit Throttle position sensor ECM |
| P0122 | Throttle position sensor output (VLU) is less than 0.2 V (1 trip detection logic) |
Throttle position sensor Open or short in VLU circuit Open in VC circuit ECM |
| P0123 | Throttle position sensor output (VLU) is more than 4.8 V (1 trip detection logic) |
Throttle position sensor Open in E2 circuit Short in VC and VLU circuits ECM |
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
- NOTICE:
- After replacing the ECM, the new ECM needs registration and initialization .
- HINT:
- If DTCs relating to different systems are output, and they share terminal E2 as their ground, check this ground circuit first.
| 1.CHECK HARNESS AND CONNECTOR (THROTTLE POSITION SENSOR - ECM) |
Disconnect the E59 ECM connectors.
Disconnect the E61 throttle position sensor connector.
Measure the resistance of the wire harness side connectors.
- Standard resistance:
Tester Connection Specified Condition VCVL (E59-73) - VC (E61-1) Below 1 Ω VLU (E59-119) - VTA (E61-3) Below 1 Ω EVLU (E59-96) - E2 (E61-2) Below 1 Ω VCVL (E59-73) or VC (E61-1) - Body ground 10 kΩ or higher VLU (E59-119) or VTA (E61-3) - Body ground 10 kΩ or higher EVLU (E59-96) or E2 (E61-2) - Body ground 10 kΩ or higher
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| OK | |
| 2.CHECK TERMINAL VOLTAGE (VC TERMINAL OF THROTTLE POSITION SENSOR) |
Disconnect the E61 sensor connector.
Turn the engine switch ON (IG).
Measure the voltage.
- Standard voltage:
Tester Connection Specified Condition VC (E61-1) - E2 (E61-2) 4.5 to 5.5 V
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| OK | |
| 3.REPLACE DIESEL THROTTLE BODY ASSEMBLY |
| NEXT | |
| 4.CHECK IF DTC OUTPUT RECURS |
Clear the DTC(s) .
Start the engine.
Let the engine idle for 60 seconds.
Repeat quick engine revving to 2,500 rpm for 30 seconds.
Check for DTC(s) .
- Result:
Display (DTC Output) Proceed to P0120, P0122 and/or P0123 A No output B
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| A | ||
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