Honda TRX400EX FOURTRAX 1999, Service Manual

Page: 232 / 263

IGNITION SYSTEM
TROUBLESHOOTING
the following before diagnosing the system.
-
Faulty spark plug
-
Loose spark plug cap or spark plug wire connections
-Water got into the spark plug cap (Leaking the ignition coil secondary voltage)
If there is no spark a t cylinder, temporarily exchange the ignition coil with a good one and perform the spark test. If there is
spark, the exchanged ignition coil
is
faulty.
No spark at spark plug
gnition coil
ixciter coil
UNUSUAL CONDITION
pulse
Low peak voltage
No peak voltage
Peak voltage is normal, but no
spark jumps at plug
Low peak voltage
No peak voltage
Low peak voltage
peak voltage.
PROBABLE CAUSE (Check in numerical order)
1. Incorrect peak voltage adaptor connections. (System is normal if mea-
sured voltage is over the specifications with reverse connections.)
2. The multimeter impedance is too low;
10 MOIDCV.
3. Cranking speed is too low.
is undercharged.
4. The sampling timing of the tester and measured pulse were not
synchronized. (System
is
normal if measured voltage is over the
standard voltage a t least once.)
5. Poorly connected connectors or an open circuit in ignition system.
6. Faulty exciter coil. (Measure peak voltage.)
7. Faulty ignition coil.
8.
Faulty ignition control module (when above No. 1 through
7
are normal.)
1. Incorrect peak voltage adaptor connections. (System is normal if mea-
sured voltage is over the specifications with reverse connections.)
2. Short circuit in engine stop switch wire.
3.
Faulty ignition switch or engine stop switch.
4. Loose or poorly connected ICM connectors.
5. Open circuit or poor connection in ground wire of
6. Faulty peakvoltage adaptor.
7. faulty exciter coil. (Measure peak voltage.)
8.
Faulty ignition pulse generator. (Measure peak voltage.)
9. Faulty ICM (when above
No. 1
through 8 are normal.)
1. Faulty spark plug or leaking ignition coil secondary current ampere.
2.
Faultv coil.
the ICM.
1. The multimeter impedance is too low; 10
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 exciter coil (when above No.
1
through
3
are normal).
1. Faulty peak voltage adaptor.
2. Faulty exciter coil.
1. The multimeter impedance is too low; 10
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 i f measured voltage i s
standard voltage a t least once.)
4. Faulty ignition pulse generator (when above
No.
1 through
3
are
normal).
1.
Faulty peak voltage adaptor.
2. Faulty ignition pulse generator.
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