Code No. P0102: Air flow Sensor Circuit Low Input




OPERATION




FUNCTION




TROUBLE JUDGMENT


Check Conditions
Judgment Criterion

FAIL-SAFE AND BACKUP FUNCTION




PROBABLE CAUSES




DIAGNOSTIC PROCEDURE


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



  • Refer to Data List Reference Table .

  1. Item 114: Air flow sensor

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. Perform voltage measurement at air flow sensor connector.



  • Disconnect connector, and measure at harness side.
  • Ignition switch: ON
  • Voltage between terminal power supply line and body earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 3.

    Repair or replace the connector, or check and repair harness between engine control relay connector terminal and air flow sensor connector terminal.

    • Check power supply line for open/short circuit.

STEP 3. Perform resistance measurement at air flow sensor connector.



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

Q. Is the check result normal?

Go to Step 6.
Go to Step 4.

STEP 4. Check harness between air flow sensor connector terminal and engine-ECU connector terminal AFSE&ECBE.



  • Check earthing line for open circuit and damage.

Q. Is the check result normal?

Go to Step 5.
Repair or replace the connector, or repair the damaged harness wire.

STEP 5. M.U.T.-III data list



  • Refer to Data List Reference Table .

  1. Item 114: Air flow sensor

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 6. Check harness between engine control relay connector terminal and air flow sensor connector terminal.



  • 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 air flow sensor connector terminal and engine-ECU connector terminal AFS.



  • Check output line for open/short circuit and damage.

Q. Is the check result normal?

Go to Step 8.
Repair or replace the connector, or repair the damaged harness wire.

STEP 8. Replace the air flow sensor.



  • After replacing the air flow sensor, re-check the trouble symptoms.

Q. Is the check result normal?

Check end.
Replace the engine-ECU.