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Chery Automobile Maintenance Manual 11 1. Diagnostic Troubleshooting Code 12 Airflow Sensor System Possible Reasons Check Area A Engine speed is above 500r/min. Setup condition B Sensor output frequency last 4 seconds below 3Hz. 1 Airflow sensor failure 2 Connector contact defect of airflow sensor, wiring open loop or short wiring 3 Engine-ECU failure Measure airflow sensor l Connect test cable MB991709 between airflow sensor and harness connector. 1. The voltage between 3# terminal and ground (at engine idle speed) Normal voltage: 2.2-3.2V 2. The voltage between 7# terminal and Normal voltage: 0-1V(at engine idle speed) 6-9V(3000rpm) Normal Replace engine ECU 1.Abnormal Check the circuit of airflow sensor 2.Abnormal Check D zone terminal of engine ECU l Connect connector l Voltage between D20 terminal and ground l Ignition switch: on (6-9V normal) Abnormal Check airflow Abnormal Repair Normal Check D zone connector of engine ECU Normal Check failure Abnormal Replace engine ECU Normal Check failure Abnormal Replace airflow sensor Abnormal Repair 1 2 3 4 5 6 7 Airflow Sensor Connector |