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








OPERATION



  • Refer to Code No. P2122: Accelerator Pedal Position Sensor (main) Circuit Low Input .
  • Refer to Code No. P2127: Accelerator Pedal Position Sensor (sub) Circuit Low Input .

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 (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 (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.

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-124 accelerator pedal position connector


Q. Is the check result normal?

Go to Step 2 .
Repair or replace the connector.

STEP 2. Perform resistance measurement at C-124 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-30 engine-ECU connector


Q. Is the check result normal?

Go to Step 4 .
Repair or replace the connector.

STEP 4. Check harness between C-124 (terminal No. 2) accelerator pedal position sensor connector and B-30 (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. Check the trouble symptoms


Q. Does trouble symptom persist?

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-124 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-30 engine-ECU connector


Q. Is the check result normal?

Go to Step 8 .
Repair or replace the connector.

STEP 8. Check harness between C-124 (terminal No. 5) accelerator pedal position sensor connector and B-30 (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-30 engine-ECU connector


Q. Is the check result normal?

Go to Step 10 .
Repair or replace the connector.

STEP 10. Check harness between C-124 (terminal No. 1) accelerator pedal position sensor connector and B-30 (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-124 (terminal No. 4) accelerator pedal position sensor connector and B-30 (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-124 (terminal No. 3) accelerator pedal position sensor connector and B-30 (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-124 (terminal No. 6) accelerator pedal position sensor connector and B-30 (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, re-check the trouble symptoms.

Q. Does trouble system persist?

Check end.
Replace the engine-ECU.