Code No. P0121: Trustful Check Throttle Position Sensor (main)




FUNCTION




TROUBLE JUDGMENT


Check Conditions
Judgement Criterion

FAIL-SAFE AND BACKUP FUNCTION




PROBABLE CAUSES




DIAGNOSIS PROCEDURE


STEP 1. M.U.T.-III diagnosis code


Q. Is any other diagnosis code than P0121 set?

Inspection chart for diagnosis code (Refer to ).
Go to Step 2.

STEP 2. M.U.T.-III data list



  • Refer to Data List Reference Table .

  1. Item 13: Throttle position sensor (main)

Q. Is the check result normal?

Go to Step 3.
Check throttle position sensor (main) system (Refer to Code No. P0122: Throttle Position Sensor (main) Circuit Low Input , P0123: Throttle Position Sensor (main) Circuit High Input ).

STEP 3. Check air intake from intake hose and inlet manifold.


Q. Is the check result normal?

Go to Step 4.
Repair.

STEP 4. Check air flow sensor.



  • Check that there is not foreign matter around air flow sensor.

Q. Is the check result normal?

Go to Step 5.
Repair.

STEP 5. M.U.T.-III diagnosis code



  • Reconfirmation of diagnosis code.

Q. Is diagnosis code set?

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