Code No. P2138: Accelerator Pedal Position Sensor (main and sub) Range/Performance Problem


OPERATION



  • Check code No. P2122: accelerator pedal position sensor (main) circuit low input (Refer to ).
  • Check code No. P2127: accelerator pedal position sensor (sub) circuit low input (Refer to ).

FUNCTION



  • Engine-ECU checks the accelerator pedal position sensor output signal characteristics for abnormal conditions.

TROUBLE JUDGMENT


Check Conditions
  • Ignition switch is "ON" position.
  • Accelerator pedal position sensor (main) output voltage is more than 0.2 V and less than 4.8 V.
  • Accelerator pedal position sensor (sub) output voltage is more than 0.2 V and less than 4.8 V.
  • Change of accelerator pedal position sensor (sub) output voltage per 25 milliseconds is less than 0.06 V.
Judgement Criterion
  • The difference is 0.4 V or more between the output voltages multiplied by two of the accelerator pedal position sensor (sub) and the output voltage of the accelerator pedal position sensor (main).

FAIL-SAFE AND BACKUP FUNCTION



  • Throttle opening degree is restricted.
  • Throttle opening degree position is in default position if accelerator pedal position sensor (sub) fails.

PROBABLE CAUSES



  • Failed accelerator pedal position sensor
  • Harness damage in accelerator pedal position sensor circuit or loose connector contact
  • Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. Connector check: C-23 accelerator pedal position sensor connector

Q. Is the check result normal?
Go to Step 2 .
Repair or replace the connector.

STEP 2. Perform resistance measurement at C-23 accelerator pedal position sensor connector.

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

Q. Is the check result normal?
Go to Step 6 .
Go to Step 3 .

STEP 3. Connector check: B-27 engine-ECU connector

Q. Is the check result normal?
Go to Step 4 .
Repair or replace the connector.

STEP 4. Check harness between C-23 (terminal No. 2) accelerator pedal position sensor connector and B-27 (terminal No. 76) engine-ECU connector.

  • Check earthing line for damage.

Q. Is the check result normal?
Go to Step 5 .
Repair the damaged harness wire.

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 ).

STEP 6. Perform resistance measurement at C-23 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 9 .
Go to Step 7 .

STEP 7. Connector check: B-27 engine-ECU connector

Q. Is the check result normal?
Go to Step 8 .
Repair or replace the connector.

STEP 8. Check harness between C-23 (terminal No. 5) accelerator pedal position sensor connector and B-27 (terminal No. 79) engine-ECU connector.

  • Check earthing line for damage.

Q. Is the check result normal?
Go to Step 5 .
Repair the damaged harness wire.

STEP 9. Connector check: B-27 engine-ECU connector

Q. Is the check result normal?
Go to Step 10 .
Repair or replace the connector.

STEP 10. Check harness between C-23 (terminal No. 1) accelerator pedal position sensor connector and B-27 (terminal No. 75) engine-ECU connector.

  • Check power supply line for damage.

Q. Is the check result normal?
Go to Step 11 .
Repair the damaged harness wire.

STEP 11. Check harness between C-23 (terminal No. 4) accelerator pedal position sensor connector and B-27 (terminal No. 78) engine-ECU connector.

  • Check power supply line for damage.

Q. Is the check result normal?
Go to Step 12 .
Repair the damaged harness wire.

STEP 12. Check harness between C-23 (terminal No. 3) accelerator pedal position sensor connector and B-27 (terminal No. 74) engine-ECU connector.

  • Check output line for damage.

Q. Is the check result normal?
Go to Step 13 .
Repair the damaged harness wire.

STEP 13. Check harness between C-23 (terminal No. 6) accelerator pedal position sensor connector and B-27 (terminal No. 77) engine-ECU connector.

  • Check output line for damage.

Q. Is the check result normal?
Go to Step 14 .
Repair the damaged harness wire.

STEP 14. Replace the accelerator pedal assembly

  • After replacing the accelerator pedal assembly, reconfirm whether the diagnosis code is set.

Q. Is the diagnosis code set?
Replace the engine-ECU.
Check end.