Mil 9 Blinks (Iat Sensor) - Honda GL1800 Service Manual

FUEL SYSTEM (Programmed Fuel Injection)

MIL 9 BLINKS (IAT SENSOR)

1. IAT Sensor Connection Inspection
Remove the top shelter (page 2-12).
Turn the ignition switch to "OFF."
Disconnect the IAT sensor 2P connector.
Check the connector for loose contacts or cor-
roded terminals.
Connect the IAT sensor 2P connector.
Place the motorcycle on its side stand.
Turn the ignition switch to "ON."
Check that the MIL blinks.
Is the MIL blinking?
NO
YES
2. IAT Sensor Power Input Line Voltage Inspection
Turn the ignition switch to "OFF."
Disconnect the IAT sensor 2P connector.
Turn the ignition switch to "ON."
Measure the voltage between the wire harness
side 2P connector terminal and ground.
Connection: Gray/blue (+) – Ground (–)
Standard: 4.75 – 5.25 V
Is the voltage within 4.75 – 5.25 V?
NO
YES
3. IAT Sensor Signal Line Voltage Inspection
Measure the voltage between the wire harness
side 2P connector terminals.
Connection: Gray/blue (+) – Green/red (–)
Standard: 4.75 – 5.25 V
Is the voltage within 4.75 – 5.25 V?
NO
YES
4. IAT Sensor Resistance Inspection
Turn the ignition switch to "OFF."
Measure the resistance between the IAT sensor
terminals (at 20 – 30° C/68 – 86° F).
Is resistance within 1 – 4 k?
NO
YES
5-22
– Temporary failure; the
normal.
– GO TO STEP 2.
– • Open or short circuit in the Gray/blue
wire.
• Loose or poorly connected ECM gray
connector.
– GO TO STEP 3.
– • Open circuit in the Green/red wire.
• Loose or poorly connected ECM
black connector.
– GO TO STEP 4.
– Faulty IAT sensor.
– Replace the ECM with a new one and
inspect again.
AT SENSOR CONNECTOR
system is
Green/red
Gray/blue
AT SENSOR TERM NALS