Code No. P2122: Accelerator Pedal Position Sensor (Main) Circuit Low Input

OPERATION

A power voltage of 5 V is applied to the accelerator pedal position sensor (terminal No. 2) from the engine-ECU or engine-A-M/T-ECU (terminal No. 85).
The power voltage is earthed to the engine-ECU or engine-A-M/T-ECU (terminal No. 84) from the accelerator pedal position sensor (terminal No. 4).
The sensor signal is inputted to the engine-ECU or engine-A-M/T-ECU (terminal No. 83) from the accelerator pedal position sensor output terminal (terminal No. 3).

FUNCTION

The accelerator pedal position sensor (main) outputs voltage which corresponds to the accelerator pedal depression.
The engine-ECU or engine-A-M/T-ECU checks whether the voltage is within a specified range.

TROUBLE JUDGMENT

Check Condition

Ignition switch is in "ON" position.

Judgment Criterion

Accelerator pedal position sensor (main) output voltage is 0.2 volt or less for 0.3 second.

PROBABLE CAUSES

Failed accelerator pedal position sensor
Open or shorted accelerator pedal position sensor (main) circuit, harness damage, or connector damage
Failed engine-ECU or engine-A-M/T-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III data list

Refer to Data List Reference Table .

Item No. 11: Accelerator pedal position sensor (main)

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: B-115 accelerator pedal position sensor connector

Q. Is the check result normal?

Go to Step 3 .

Repair or replace the connector.

STEP 3. Check accelerator pedal position sensor itself.

Check accelerator pedal position sensor itself (Refer to ).

Q. Is the check result normal?

	Go to Step 4 .

	Replace the accelerator pedal assembly.

STEP 4. Perform voltage measurement at B-115 accelerator pedal position sensor connector.

Disconnect connector, and measure at harness side.
Ignition switch: ON
Voltage between terminal No. 2 and earth.

OK: 4.9 - 5.1 V

Q. Is the check result normal?

Go to Step 8 .

Go to Step 5 .

STEP 5. Connector check: A-09 engine-ECU connector or engine-A-M/T-ECU connector

Q. Is the check result normal?

Go to Step 6 .

Repair or replace the connector.

STEP 6. Check harness between B-115 (terminal No. 2) accelerator pedal position sensor connector and A-09 (terminal No. 85) engine-ECU or engine-A-M/T-ECU connector.

Check power supply line for open/short circuit.

Q. Is the check result normal?

Go to Step 7 .

Repair the damaged harness wire.

STEP 7. M.U.T.-III data list

Refer to Data List Reference Table .

Item No. 11: Accelerator pedal position sensor (main)

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 or engine-A-M/T-ECU then perform the variant coding (Refer to GROUP 00 - Precautions Before Service - How to Perform Variant Coding ).

STEP 8. Connector check: A-09 engine-ECU connector or engine-A-M/T-ECU connector

Q. Is the check result normal?

Go to Step 9 .

Repair or replace the connector.

STEP 9. Check harness between B-115 (terminal No. 2) accelerator pedal position sensor connector and A-09 (terminal No. 85) engine-ECU connector or engine-A-M/T-ECU connector.

Check power supply line for damage.

Q. Is the check result normal?

Go to Step 10 .

Repair the damaged harness wire.

STEP 10. Check harness between B-115 (terminal No. 3) accelerator pedal position sensor connector and A-09 (terminal No. 83) engine-ECU connector or engine-A-M/T-ECU connector.

Check output line for open/short circuit and damage.

Q. Is the check result normal?

Go to Step 7 .

Repair the damaged harness wire.