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.
  • Change of accelerator pedal position sensor (sub) output voltage per 25 milliseconds is less than 0.06 V.
Judgement Criterion
  • Voltage obtained with the formula given below is more than 0.4 V: accelerator pedal position sensor (sub) voltage - accelerator pedal position sensor (main) voltage
note The accelerator pedal position sensor voltage used for the judgment is converted into the accelerator pedal position sensor voltage for the internal processing by the engine-ECU.

Check Conditions



  • Ignition switch is "ON" position.
  • Change of accelerator pedal position sensor (main) output voltage per 25 milliseconds is less than 0.06 V.

Judgement Criterion



  • Voltage obtained with the formula given below is more than 0.4 V: accelerator pedal position sensor (main) voltage - accelerator pedal position sensor (sub) voltage
note The accelerator pedal position sensor voltage used for the judgment is converted into the accelerator pedal position sensor voltage for the internal processing by the engine-ECU.

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. Perform resistance measurement at accelerator pedal position sensor connector.

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

Q. Is the check result normal?
Go to Step 4.
Go to Step 2.

STEP 2. Check harness between accelerator pedal position sensor connector terminal and engine-ECU connector terminal APSE.

  • Check earthing line for damage.

Q. Is the check result normal?
Go to Step 3.
Repair or replace the connector, or repair the damaged harness wire.

STEP 3. 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 4. Perform resistance measurement at accelerator pedal position sensor connector.

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

Q. Is the check result normal?
Go to Step 6.
Go to Step 5.

STEP 5. Check harness between accelerator pedal position sensor connector terminal and engine-ECU connector terminal EV.

  • Check earthing line for damage.

Q. Is the check result normal?
Go to Step 3.
Repair or replace the connector, or repair the damaged harness wire.

STEP 6. Check harness between accelerator pedal position sensor connector terminal and engine-ECU connector terminal APS5.

  • Check power supply line for damage.

Q. Is the check result normal?
Go to Step 7.
Repair or replace the connector, or repair the damaged harness wire.

STEP 7. Check harness between accelerator pedal position sensor connector terminal and engine-ECU connector terminal 5VV.

  • 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 accelerator pedal position sensor connector terminal and engine-ECU connector terminal APSM.

  • Check output line for damage.

Q. Is the check result normal?
Go to Step 9.
Repair or replace the connector, or repair the damaged harness wire.

STEP 9. Check harness between accelerator pedal position sensor connector terminal and engine-ECU connector terminal APSS.

  • Check output line for damage.

Q. Is the check result normal?
Go to Step 10.
Repair or replace the connector, or repair the damaged harness wire.

STEP 10. 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.