Checking The Engine Ecm Circuit - Yamaha F150A Service Manual

Main relay input voltage:
Terminal "a"–Terminal "b"
12 V (battery voltage)
5. Turn the engine start switch to OFF, and
then install the main relay.

Checking the engine ECM circuit

1. Disconnect the engine ECM coupler "a".
a
2. Check for continuity between the engine
ECM coupler terminals and ground.
a
b
Wiring harness continuity:
Terminal 32–Ground
Terminal 42–Ground
3. Measure the input voltage at the engine
ECM coupler terminal and ground.
Engine ECM input voltage:
Terminal 16–Ground
4. Turn the engine start switch to ON, and
then measure the input voltage at the
engine
ground.
5-14
Engine control unit and component
32
42
16
12 V (battery voltage)
ECM coupler
0
1
2
3
4
5
6
7
8
9
terminal and
10
A