Honda BF40D Mode D'emploi page 427

DTC 10-2: IAT sensor voltage is too high
1) Symptom reproduction test
a. Turn the combination switch OFF. Disconnect the
IAT sensor 2P connector
again.
b. Clear the DTC (P. 5-12).
• Continue the procedure when the DTC does not
clear.
c. Turn the combination switch ON. Measure the IAT
sensor voltage using the HDS (Dr. H or pocket
tester).
Is the measurement within 0.078 - 4.92V?
YES - Temporary failure (Disappears.)
NO - Go to "2) IAT sensor signal line open-circuit
inspection."
2) IAT sensor signal line open-circuit inspection
a. Turn the combination switch OFF and disconnect
the IAT sensor 2P connector
b. Turn the combination switch ON. Measure the
voltage between the IAT sensor 2P connector
main wire harness side No.1 (Red/Yellow) terminal
and the engine ground.
IAT SENSOR 2P CONNECTOR
MAIN WIRE HARNESS SIDE
1
VIEWED FROM THE TERMINAL SIDE
Is the measurement within 4.30 - 5.25V?
YES - Go to "3) IAT sensor GND line open-circuit
inspection."
NO - Repair open in the main wire harness
between the ECM and the IAT sensor.
3) IAT sensor GND line open-circuit inspection
once and connect it
1
.
1
4) IAT sensor inspection
1
TA (Red/Yellow)
427
• Turn the combination switch OFF. Check for
continuity between the IAT sensor 2P connector
main wire harness side No.2 (Green/Red) terminal
and the engine ground.
IAT SENSOR 2P CONNECTOR
MAIN WIRE HARNESS SIDE
1
SG2
(Green/Red)
VIEWED FROM THE TERMINAL SIDE
Is there continuity?
YES - Go to "4) IAT sensor inspection."
NO - Repair open in the main wire harness
between the ECM and the IAT sensor.
a. Connect the IAT sensor 2P connector
b. Turn the combination switch ON. Measure the
sensor temperature using the HDS (Dr. H or pocket
tester).
Does the measurement correspond to the ambient
temperature?
YES - Replace the ECM with a new one and
recheck.
NO - Replace the IAT sensor with a new one and
recheck.
1
.
1
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