Impreza Coupe FWD F4-1820cc 1.8L SOHC (1995)
Mass Air Flow Sensor: Testing and Inspection
DTC 23 - MASS AIR FLOW SENSOR
Diagnosis
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The Mass Air Flow Sensor signal is abnormal.
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The harness connector between Engine Control Module (ECM) and Mass Air Flow Sensor is in short or open.
Trouble Symptom
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Erroneous idling.
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Engine stalls.
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Poor driving performance
1. Check input signal for ECM.
a. Turn Ignition Switch to "ON".
b. Measure voltage between ECM and body.
Connector & Terminal / Specified Voltage:
(E3O) No. 5 - Body / 0 - 0.3 Volts
(E31) No. 1 - Body / 0 Volts
c. Start Engine, and idle it.
d. Measure voltage between ECM and body while Engine is idling.
Connector & Terminal / Specified Voltage:
(E3O) No. 5 - Body / 0.8 - 1.2 Volts
(E31) No. 1 - Body / 0 Volts
2. Check power supply to Mass Air Flow Sensor.
a. Turn Ignition Switch to "OFF".
b. Disconnect connector from Mass Air Flow Sensor.
c. Turn Ignition Switch to "ON".
