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 JUDGEMENT

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.
The RMS (Forward) and FCM-LS are prohibited. <Vehicles with FCM-LS>

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 APSE line and earth.

OK: Continuity (2 Ω or less)

Q. Is the check result normal?

	Go to Step 4.

	Go to Step 2.

STEP 2. Check of damage between accelerator pedal position sensor connector and engine-ECU connector.

Q. Is the check result normal?

	Go to Step 3.

	Repair the connector(s) or wiring harness.

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 APE line and earth.

OK: Continuity (2 Ω or less)

Q. Is the check result normal?

	Go to Step 6.

	Go to Step 5.

STEP 5. Check of damage in APE line between accelerator pedal position sensor connector and engine-ECU connector.

Q. Is the check result normal?

	Go to Step 3.

	Repair the connector(s) or wiring harness.

STEP 6. Check of damage in APS5 line between accelerator pedal position sensor connector and engine-ECU connector.

Q. Is the check result normal?

	Go to Step 7.

	Repair the connector(s) or wiring harness.

STEP 7. Check of damage in AP5 line between accelerator pedal position sensor connector and engine-ECU connector.

Q. Is the check result normal?

	Go to Step 8.

	Repair the connector(s) or wiring harness.

STEP 8. Check of damage in APSM line between accelerator pedal position sensor connector and engine-ECU connector.

Q. Is the check result normal?

	Go to Step 9.

	Repair the connector(s) or wiring harness.

STEP 9. Check of damage in APSS line between accelerator pedal position sensor connector and engine-ECU connector.

Q. Is the check result normal?

	Go to Step 10.

	Repair the connector(s) or wiring harness.

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.