Code No. P0103: Air Flow Sensor Circuit High Input
OPERATION
- Power is supplied by the engine control relay connector
terminal to the air flow sensor connector terminal.
- Power is supplied by the engine-ECU connector terminal AFS5 to the air flow sensor
connector terminal, and the air flow sensor connector terminal is earthed through the engine-ECU connector
terminal AFSE.
- The air flow sensor connector terminal 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 JUDGMENT
Check Condition
- More than 3 seconds have passed since the ignition switch was turned to "ON" position.
- Air flow sensor output voltage is more than 4.9 V (corresponding to an air flow
rate of 300 g/sec or more) for 2 seconds.
FAIL-SAFE AND BACKUP FUNCTION
- Fuel control is carried out using throttle opening degree and engine speed
in accordance with preset map.
PROBABLE CAUSES
- Failed air flow sensor
- Open circuit or harness damage in air flow sensor circuit or loose connector contact
- Failed engine-ECU
DIAGNOSIS PROCEDURE |
STEP 1. M.U.T.-III data list |
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Q.
Is the check result normal?
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Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection
Service Points - How to Cope with Intermittent Malfunctions ). |
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Go to Step 2. |
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STEP 2. Perform resistance measurement at air flow sensor connector. |
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OK: Continuity (2 Ω or less) |
Q.
Is the check result normal?
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Go to Step 5. |
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Go to Step 3. |
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STEP 3. Check harness between air flow sensor connector terminal and engine-ECU connector terminal AFSE. |
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Q.
Is the check result normal?
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Go to Step 4. |
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Repair or replace the connector, or repair the damaged harness wire. |
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STEP 4. M.U.T.-III data list |
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Q.
Is the check result normal?
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Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection
Service Points - How to Cope with Intermittent Malfunctions ). |
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Replace the engine-ECU. |
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STEP 5. M.U.T.-III data list |
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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 ). |
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Go to Step 6. |
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STEP 6. Replace the air flow sensor |
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Q.
Is the diagnosis code set?
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Replace the engine-ECU. |
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Check end. |
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