Code No. P2127: Accelerator Pedal Position Sensor (sub) Circuit Low 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. 78).
The power voltage is earthed to the engine-ECU (terminal No. 79) from the accelerator pedal position sensor (terminal No. 5).
The sensor signal is inputted to the engine-ECU (terminal No. 77) 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 Condition

Ignition switch is "ON" position.

Judgement Criterion

Accelerator pedal position sensor (sub) output voltage is less than 0.2 V.

PROBABLE CAUSES

Failed accelerator pedal position sensor
Open/short circuit or harness damage 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 .

Item 12: 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-123 accelerator pedal position sensor connector

Q. Is the check result normal?

	Go to Step 3 .

	Repair or replace the connector.

STEP 3. Perform voltage measurement at C-123 accelerator pedal position sensor connector.

Disconnect connector, and measure at harness side.
Ignition switch: ON
Voltage between terminal No. 4 and earth.

OK: 4.9 - 5.1 V

Q. Is the check result normal?

	Go to Step 7 .

	Go to Step 4 .

STEP 4. Connector check: B-09 engine-ECU connector

Q. Is the check result normal?

	Go to Step 5 .

	Repair or replace the connector.

STEP 5. Check harness between C-123 (terminal No. 4) accelerator pedal position sensor connector and B-09 (terminal No. 78) engine-ECU connector.

Check power supply line for open/short 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 .

Item 12: 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.

STEP 7. Connector check: B-09 engine-ECU connector

Q. Is the check result normal?

	Go to Step 8 .

	Repair or replace the connector.

STEP 8. Check harness between C-123 (terminal No. 4) accelerator pedal position sensor connector and B-09 (terminal No. 78) engine-ECU connector.

Check power supply line for damage.

Q. Is the check result normal?

	Go to Step 9 .

	Repair the damaged harness wire.

STEP 9. Check harness between C-123 (terminal No. 6) accelerator pedal position sensor connector and B-09 (terminal No. 77) engine-ECU connector.

Check output line for open/short circuit and damage.

Q. Is the check result normal?

	Go to Step 10 .

	Repair the damaged harness wire.

STEP 10. Replace the accelerator pedal assembly

After replacing the accelerator pedal assembly, re-check the trouble symptoms.

Q. Is the check result normal?

	Check end.

	Replace the engine-ECU.