TOHATSU BFT75A Service Manual page 285

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IGNITION SYSTEM
8. Ignition coil power/ground line open circuit inspection
Turn the combination switch OFF.
Disconnect the ignition coil 3P connector.
Turn the combination switch ON.
Measure the voltage between the ignition coil 3P
connector main wire harness side No.3 (Yellow/
Black) terminal and No.2 (Black) terminal.
Does battery voltage exist?
YES
NO
9. Ignition coil signal line open or short circuit inspection
Turn the combination switch OFF.
Check for continuity between the ECM connector A
connector main wire harness side No.1 terminal.
There should be continuity.
Check for continuity between the ignition coil 3P connector main wire harness side No.1 terminal and
engine ground.
There should be no continuity.
Are they normal?
YES
NO
10. Ignition coil replacement
Replace the ignition coil(s) and restart the engine.
Does the engine start properly?
YES
NO
8-4
– GO TO STEP 9.
– • Repair open in the main wire harness
between the No.3 fuse and ignition coil.
• Repair open in the main wire harness
between the ignition coil and ground.
– GO TO STEP 10.
– Repair open or short in the main wire harness between the ECM and ignition coil.
– Faulty original ignition coil(s).
– Replace the ECM with a new one and recheck.
IGNITION COIL 3P CONNECTOR
MAIN WIRE HARNESS SIDE
IGP 1/2/3/4
(Yellow/Black)
main wire harness side and ignition coil 3P
GND1
(Black)