[ Model - ECLIPSE CROSS / Year - 2018 ]
2018 / ECLIPSE CROSS / EC - Workshop Manual
13 -FUEL > 13A-DIRECT INJECTION AND MULTIPOINT FUEL INJECTION (DI AND MPI) > TROUBLESHOOTING > DIAGNOSIS CODE PROCEDURES > CODE NO. P0102 AIR FLOW SENSOR CIRCUIT LOW INPUT
Code No. P0102: Air Flow Sensor Circuit Low Input
 
 
 
 
OPERATION
  • Power is supplied by the engine control relay to the air flow sensor.
  • Power is supplied by the engine-ECU connector terminal AFS5 to the air flow sensor, and the air flow sensor is earthed through the engine-ECU connector terminal AFSE.
  • The air flow sensor outputs a sensor signal, which is input into the engine-ECU connector terminal AFS.
 
 
FUNCTION
  • The air flow sensor outputs current that varies in accordance with the intake air volume.
  • The engine-ECU uses the amperage output by the air flow sensor and the engine speed signal in order to determine the basic injection duration of the injector.
 
 
TROUBLE JUDGEMENT
Check Condition
  • More than 3 seconds have passed since the ignition switch was turned to "ON" position.
Judgement Criterion
  • Air flow sensor output voltage is less than 0.2 V for 2 seconds.
 
 
FAIL-SAFE AND BACKUP FUNCTION
  • Estimate the throttle opening degree and the amount of intake air given by a normal sensor, and then carry out the fuel control.
  • Supercharging pressure is restricted.
 
 
PROBABLE CAUSES
  • Failed air flow sensor
  • Open/short circuit or harness damage in air flow sensor circuit or loose connector contact
  • Failed engine-ECU
 
 
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-IIISE data list
  • Data list reference table (Refer to ).
    1. Item 10: Air flow sensor
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
Is the check result normal?
Go to Step 3.
Repair the connector(s), or check and repair of short to earth, and open circuit in power supply line between engine control relay connector and air flow sensor connector.
 
STEP 3. Perform voltage measurement at air flow sensor connector.
  • Use special tool test harness (MB991709) to connect connector, and measure at pick-up harness.
  • Ignition switch: "ON"
  • Voltage between terminal engine-ECU AFS5 line and body earth.
OK: 4.9 - 5.1 V
Is the check result normal?
Go to Step 5.
Go to Step 4.
 
STEP 4. Check of short to earth, and open circuit in AFS5 line between air flow sensor connector and engine-ECU connector.
Is the check result normal?
Go to Step 5.
Repair the connector(s) or wiring harness.
 
STEP 5. Check of open circuit, and short circuit in AFS line between air flow sensor connector and engine-ECU connector.
Is the check result normal?
Go to Step 6.
Repair the connector(s) or wiring harness.
 
STEP 6. Check of damage in power supply line between engine control relay connector and air flow sensor connector.
Is the check result normal?
Go to Step 7.
Repair the connector(s) or wiring harness.
 
STEP 7. M.U.T.-IIISE data list
  • Data list reference table (Refer to ).
    1. Item 10: Air flow sensor
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 8.
 
STEP 8. Replace the air flow sensor
  • After replacing the air flow sensor, reconfirm whether the diagnosis code is set.
Is the diagnosis code set?
Replace the engine-ECU.
Check end.