Code No. P1234: Trustful Check Throttle Position Sensor (Sub)


FUNCTION



  • Compare the actual measurement of volumetric efficiency by an air flow sensor signal with volumetric efficiency estimated from a throttle position sensor (sub) signal.

TROUBLE JUDGMENT


Check Condition
  • The difference between the actual volumetric efficiency and the volumetric efficiency estimated by the throttle position sensor (sub) is 0% or more. Or, the volumetric efficiency is 60% or less.
  • The engine speed is 750 - 3000r/min. Or, the throttle position sensor (sub) output voltage is 3 volts or less.
Judgement Criterion
  • The difference between the actual volumetric efficiency and the volumetric efficiency estimated by the throttle position sensor (sub) is 33% or more.

PROBABLE CAUSES



  • Failed throttle position sensor (sub)
  • Harness damage in throttle position sensor (sub) circuit or loose connector contact
  • Failed intake air system
  • Failed engine-ECU

DIAGNOSIS PROCEDURE

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

Q. Is any other diagnosis code than P1234 output?
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 15: Throttle position sensor (sub)

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 3 .

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

Q. Is the check result normal?
Replace the engine-ECU.
Repair.