TOHATSU BFT 250A, Service Manual

Page: 285 / 639

8-3
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IGNITION SYSTEM
IGNITION SYSTEM TROUBLESHOOTING
NO SPARK(S)
1. MIL inspection
Turn the combination switch ON and check that the MIL stays ON.
Does the MIL stay ON?
YES – PGM-FI troubleshooting (page 5-6)
NO – GO TO STEP 2.
2. Emergency stop switch clip inspection
Check the emergency stop switch clip.
Is the emergency stop switch clip connected?
YES – GO TO STEP 3.
NO – Set the clip securely.
3. Direct ignition coil inspection
Temporarily exchange the direct ignition coil with a known good direct ignition coil and perform the spark
test.
Is there spark?
Sparks– Faulty original direct ignition coil.
One plug has no spark – GO TO STEP 4.
All plugs have no sparks – GO TO STEP 5.
4. Direct ignition coil signal line open circuit inspection
Turn the combination switch OFF.
Disconnect the ECM connector A
.
Check for open or short circuit between the direct ignition coil 3P connector main wire harness side No.1
terminal and ECM connector A
terminal of the same colors.
Is the circuit normal?
YES – GO TO STEP 6.
NO – Repair open or short in the main wire harness between the ECM and direct ignition coil.
5. Fuse inspection
Check for a blown No.5 (15 A) fuse.
Is the fuse blown?
YES – Replace the blown fuse and check for short in the main wire harness or incorrect load by referring
to the fuse load chart (page 4-16).
NO – GO TO STEP 6.
6. Direct ignition coil power/ground line open circuit inspection
Turn the combination switch OFF.
Disconnect the direct ignition coil 3P connector.
Turn the combination switch ON.
Measure the voltage at the direct ignition coil 3P
connector main wire harness side No.2 terminal and
No.3 terminal.
Does battery voltage exist?
YES – GO TO STEP 7.
NO – Repair open in the main wire harness
between the ECM and direct ignition coil.
DIRECT IGNITION COIL 3P CONNECTOR
MAIN WIRE HARNESS SIDE
PHC 1/2/3/4/5/6
(Yellow/Black)
GND1
(Black)