Inspect The Air Flow Sensor Signal Unit - Hino Motors HINO 155 series Workshop Manual

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6
Inspect the air flow sensor power supply
B+
Do the measurements meet the standard value?
Go to step 7.
7

Inspect the air flow sensor signal unit

E74
D
Do the measurements meet the standard value?
Go to step 8.
ENGINE (J05E)/TROUBLESHOOTING
1. Connect the signal check harness to engine ECU.
E2G
2. Set the starter key to the "ON" position.
3. Use the electrical tester to measure the voltage between the termi-
nals of the air flow sensor vehicle side connector.
SHTS021270300651
YES
1. Set the starter key to the "LOCK" position.
E78
2. Connect the air flow sensor connector.
3. Start the engine.
4. Use an oscilloscope to measure the signal voltage between the
terminals of the engine ECU (signal check harness).
SHTS021270300652
YES
Measurement
conditions connections
Air flow sensor
vehicle side con-
Starter key: ON
nector terminals
+B – E2G
Replace the engine ECU.
Measurement
conditions connections
Engine ECU
After warm up, the (the signal check
engine idling con- harness)
VG (E74) –
dition
EVG (E78)
Replace the air flow sensor.
Perform "After-inspection work" of INFOR-
MATION section.
Tester
Standard values
11.5 – 13.5 V
NO
Tester
Standard values
5 – 6 kHz
NO