Baro/Map Sensors; Output Voltage Inspection - Honda GL1800 Service Manual

4. Turn the ignition switch to "OFF."
Measure the voltage between the Black/yellow
wire terminal (+) and Brown/black wire terminal
of the fuel pump relay connector.
Turn the ignition switch to "ON."
There should be battery voltage for a few
seconds.
• If there is battery voltage for a few seconds,
the system is OK; check for loose contacts or
corroded terminals.
• If there is no voltage, GO TO STEP 5.
5. Turn the ignition switch to "OFF."
Remove the top shelter (page 2-11).
Disconnect the ECM 22P black connector.
Check the connector for loose contacts or cor-
roded terminals.
Check for continuity between the Brown/black
wire terminals of the fuel pump relay and ECM
22P black connectors.
There should be continuity.
• If there is no continuity, repair the open circuit
in the Brown/black wire.
• If there is continuity, replace the ECM with a
new one and inspect again.

BARO/MAP SENSORS

OUTPUT VOLTAGE INSPECTION

Connect the ECM test harness to the ECM connec-
tors (page 5-11).
Turn the ignition switch to "ON" and engine stop
switch to " ."
Measure the voltage at the ECM test harness con-
nector terminals (page 5-11).
CONNECTION:
BARO sensor: B15 (+) – C4 (–)
MAP sensor: B4 (+) – C4 (–)
STANDARD: 2.7 – 3.1 V
The output voltage (above) is measured under the
standard atmosphere (1 atm = 1,030 hPa).
The output voltage is changed by altitude as shown
in the chart, because it varies in accordance with the
atmospheric pressure.
FUEL SYSTEM (Programmed Fuel Injection)
FUEL PUMP RELAY CONNECTOR
lack/yellow
ECM 22P BLACK CONNECTOR
(viewed from the terminal side)
Brown/black
UEL PUMP RELAY
CONNECTOR
3.5
3.1
3.0
.763
.7
.5
.0
1.5
1.0
0.5
0
500
(1,650)
rown/black
.6
.5
.46
.1
1,000 1,500 ,000 :m
(4,950) (6,600) (feet)
(3,300)
5-67