Code No. P2128: Accelerator Pedal Position Sensor (sub) Circuit High Input




OPERATION



  • A power voltage of 5 V is applied to the accelerator pedal position sensor (terminal No. 4) from the engine-ECU (terminal No. 112).
  • The power voltage is earthed to the engine-ECU (terminal No. 114) from the accelerator pedal position sensor (terminal No. 5).
  • The sensor signal is inputted to the engine-ECU (terminal No. 113) from the accelerator pedal position sensor output terminal (terminal No. 6).

FUNCTION



  • The accelerator pedal position sensor (sub) outputs voltage which corresponds to the accelerator pedal depression.
  • The engine-ECU checks whether the voltage is within a specified range.

TROUBLE JUDGMENT


Check Conditions
  • Battery positive voltage is 6 - 16 V
  • 2 seconds later after the ignition switch has been in "ON" position or the engine has started up
  • Accelerator pedal position sensor (main) is normal
  • Accelerator pedal position sensor (main) output voltage is 0.2 V or higher and 2.8 V or lower.
Judgment Criterion
  • Accelerator pedal position sensor (main) output voltage exceeds 2.4 V for 0.3 seconds.

PROBABLE CAUSES



  • Failed accelerator pedal position sensor
  • Open/short circuit in accelerator pedal position sensor circuit or loose connector contact
  • Failed engine-ECU

DIAGNOSIS PROCEDURE

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

  • Refer to Data List Reference Table .

  1. Item 10: Accelerator pedal 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 2 .

STEP 2. Connector check: C-115 accelerator pedal position sensor connector

Q. Is the check result normal?

Go to Step 3 .

Repair or replace the connector.

STEP 3. Perform resistance measurement at C-115 accelerator pedal position sensor connector.


  • Disconnect connector, and measure at harness side.
  • Resistance between terminal No. 5 and earth.
OK: Continuity (2 Ω or less)

Q. Is the check result normal?

Go to Step 7 .

Go to Step 4 .

STEP 4. Connector check: C-103 engine-ECU connector

Q. Is the check result normal?

Go to Step 5 .

Repair or replace the connector.

STEP 5. Check harness between C-115 (terminal No. 5) accelerator pedal position sensor connector and C-103 (terminal No. 114) engine-ECU connector.



  • Check earthing line for open circuit.

Q. Is the check result normal?

Go to Step 6 .

Repair the damaged harness wire.

STEP 6. M.U.T.-III data list

  • Refer to Data List Reference Table .

  1. Item 10: Accelerator pedal 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 ).
Replace the engine-ECU. When the engine-ECU is replaced, write the chassis number (Refer to GROUP 00 - How to Perform Chassis Number Writing ). After replacing the engine-ECU, register the injector identification code and learn fuel injection (Refer to GROUP 00 - Precautions Before Service - What The Common Rail Engine Learns ).

STEP 7. Replace the accelerator pedal position sensor

  • After replacing the accelerator position sensor, re-check the trouble symptoms.

Q. Is the check result normal?
The check is end.
Replace the engine-ECU. When the engine-ECU is replaced, write the chassis number (Refer to GROUP 00 - How to Perform Chassis Number Writing ). After replacing the engine-ECU, register the injector identification code and learn fuel injection (Refer to GROUP 00 - Precautions Before Service - What The Common Rail Engine Learns ).