Honda CBR650F Service Manual page 134

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TROUBLESHOOTING
• Inspect the following before diagnosing the system.
– Faulty spark plug
– Loose spark plug cap or spark plug wire connection
– Water got into the spark plug cap (Leaking the ignition coil secondary current)
• If there is no spark at cylinder, temporarily exchange the ignition coil with a known good one and perform the spark test. If there
is spark, the original ignition coil is faulty.
• "Initial voltage" of the ignition primary coil is the battery voltage with the ignition switch turned ON and engine stop switch turned
" " (The engine is not cranked by the starter motor).
No spark at spark plug
Unusual condition
Ignition coil No initial voltage with the ignition
primary voltage switch turned ON and engine stop
switch turned " " (Other electrical
components are normal).
Initial voltage is normal, but it drops by
2 – 4 V while cranking the engine.
Initial voltage is normal but there is no
peak voltage while cranking the
engine.
Initial voltage is normal but peak
voltage is lower than the standard
value.
Initial and peak voltages are normal
but no spark jumps.
CKP sensor Peak voltage is lower than standard
value.
No peak voltage
Probable cause (Check in numerical order)
1. An open circuit in the Black wire between the fuel pump
relay and ignition coil.
2. Faulty fuel pump relay or its related circuits.
3. Loose or poor connection of the primary terminal, or an
open circuit in the primary coil.
4. Faulty ECM (in case when the initial voltage is normal with
the ECM connector disconnected).
1. Incorrect peak voltage adaptor connections (System is
normal if measured voltage is over the specifications with
reverse connections).
2. Battery is undercharged (Voltage drops largely when the
engine is started).
3. No voltage between the Black/blue (+) wire and body
ground (–) at the ECM connector or loose ECM connection.
4. An open circuit or loose connection in the Green wire of the
ECM.
5. An open circuit or loose connection in the Green/blue or
Green/white wire between the ignition coil and ECM.
6. Faulty sidestand switch or neutral switch.
7. Loose or poor connection or an open circuit in No. 6 related
wires.
– Sidestand switch line: Green/white, Black/blue, Black
and Green
– Neutral switch line: Green/red and Black
8. Faulty CKP sensor (Measure peak voltage).
9. Faulty ECM (in case when above No. 1 through 8 are
normal).
1. Incorrect peak voltage adaptor connections.
2. Faulty peak voltage adaptor.
3. Faulty CKP sensor.
4. Faulty ECM (in case when above No. 1 through 3 are
normal).
1. The multimeter impedance is too low; below 10 MΩ/DCV.
2. Cranking speed is too slow (Battery is undercharged).
3. The sampling timing of the tester and measured pulse were
not synchronized (System is normal if measured voltage is
over the standard voltage at least once).
4. Faulty ECM (in case when above No. 1 through 3 are
normal).
1. Faulty spark plug or leaking ignition coil secondary current.
2. Faulty ignition coil.
1. The multimeter impedance is too low; below 10 MΩ/DCV.
2. Cranking speed is too low (Battery is undercharged).
3. The sampling timing of the tester and measured pulse were
not synchronized (System is normal if measured voltage is
over the standard voltage at least once).
4. Faulty CKP sensor (in case when above No. 1 through 3
are normal).
1. Faulty peak voltage adaptor.
2. Faulty CKP sensor.
IGNITION SYSTEM
5-3