Honda GL1800 Service Manual page 156

3. Vehicle Speed Sensor Line Voltage Inspection
Measure the voltage between the wire harness
side 3P connector terminals.
Connection: Brown/white (+) – Green (–)
Standard: Battery voltage
Does battery voltage exist?
NO – Open circuit in the Green wire.
YES – GO TO STEP 4.
4. Vehicle Speed Sensor Line Short Circuit
Inspection
Turn the ignition switch to "OFF."
Disconnect the ECM 22P gray connector.
Check for continuity between the White/black
wire terminal of the wire harness side 3P con-
nector and ground.
Is there continuity?
YES – Short circuit in the White/black wire.
NO – GO TO STEP 5.
5. Vehicle Speed Sensor Line Continuity
Inspection
Check for continuity between the White/black
wire terminals of the vehicle speed sensor 3P
connector and ECM 22P connector.
Is there continuity?
NO – Open circuit in the White/black wire.
YES – GO TO STEP 6.
6. Vehicle Speed Sensor Pulse Signal Voltage
Inspection
Connect the vehicle speed sensor 3P connector.
Connect the test harness set to the ECM gray
connectors (page 5-11).
Shift the transmission into neutral and turn the
ignition switch to "ON."
Measure the voltage at the test pin box terminal
and ground while slowly turning the rear wheel
by hand.
Connection: No. 35 (+) – Ground (–)
Standard: 0 to 5 V pulse voltage
Is the voltage within the standard value?
NO – Faulty vehicle speed sensor.
YES – Replace the ECM with a new one and
inspect again.
FUEL SYSTEM (Programmed Fuel Injection)
White/black
CM 22P GRAY CONN CTOR
(viewed from the terminal side)
o. 35 (+)
5-25