Code No. P0123: Throttle Position Sensor (main) Circuit High Input




OPERATION




FUNCTION




TROUBLE JUDGEMENT


Check Condition
Judgement Criterion

FAIL-SAFE AND BACKUP FUNCTION




PROBABLE CAUSES




DIAGNOSIS PROCEDURE


STEP 1. M.U.T.-III data list



  • Data list reference table (Refer to ).

  1. Item 13: Throttle position sensor (main)

Q. Is the check result normal?

Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
Go to Step 2.

STEP 2. Perform voltage measurement at electronic-controlled throttle valve connector.



  • Disconnect connector, and measure at harness side.
  • Power supply mode of electric motor switch: ACC
  • Voltage between terminal engine-ECU TPS5 line and body earth.
OK: 4.9 - 5.1 V

Q. Is the check result normal?

Go to Step 5.
Go to Step 3.

STEP 3. Check harness between electronic-controlled throttle valve connector terminal and engine-ECU connector terminal TPS5.



  • Check power supply line for open/short circuit.

Q. Is the check result normal?

Go to Step 4.
Repair or replace the connector, or repair the damaged harness wire.

STEP 4. M.U.T.-III data list



  • Data list reference table (Refer to ).

  1. Item 13: Throttle position sensor (main)

Q. Is the check result normal?

Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
Replace the engine-ECU.

STEP 5. Perform resistance measurement at electronic-controlled throttle valve connector.



  • Disconnect connector, and measure at harness side.
  • Resistance between terminal engine-ECU TPSE line and body earth.
OK: Continuity (2 Ω or less)

Q. Is the check result normal?

Go to Step 7.
Go to Step 6.

STEP 6. Check harness between electronic-controlled throttle valve connector terminal and engine-ECU connector terminal TPSE.



  • Check earthing line for open circuit and damage.

Q. Is the check result normal?

Go to Step 4.
Repair or replace the connector, or repair the damaged harness wire.

STEP 7. Check harness between electronic-controlled throttle valve connector terminal and engine-ECU connector terminal TPS5.



  • Check power supply line for damage.

Q. Is the check result normal?

Go to Step 8.
Repair or replace the connector, or repair the damaged harness wire.

STEP 8. Check harness between electronic-controlled throttle valve connector terminal and engine-ECU connector terminal TPSM.



  • Check output line for open circuit and damage.

Q. Is the check result normal?

Go to Step 9.
Repair or replace the connector, or repair the damaged harness wire.

STEP 9. M.U.T.-III data list



  • Data list reference table (Refer to ).

  1. Item 13: Throttle position sensor (main)

Q. Is the check result normal?

Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
Go to Step 10.

STEP 10. Replace the electronic-controlled throttle valve



  • After replacing the electronic-controlled throttle valve, reconfirm whether the diagnosis code is stored.

Q. Is the diagnosis code stored?

Replace the engine-ECU.
Check end.