Ignition System Troubleshooting; No Spark At Spark Plug - Honda Fourtrax Rancher AT 2004 Service Manual

IGNITION SYSTEM
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 voltage)
• If the engine speed will not rise above 2,200 rpm with the gearshift lever in "A" position, inspect the following:
- Gearshift lever linkage adjustment (page 12-15)
- Reverse switch (page 24-42)
- Drive, neutral switch (page 24-42)
• If the engine speed will not rise above 1,750 rpm with the front brake lever released and the gearshift lever in "0 " posi-
tion, inspect the brake switch (page 22-21) and its installation condition.
No spark at spark plug
UNUSUAL CONOmON PROBABLE CAUSE Check in numerical
orderL
Ignition coil low peak voltage.
,.
Incorrect peak voltage adapter connections. (System is
primary normal if measured voltage is over the specifications
voltage with reverse connections.)
2. The multimeter impedance is too low.
3. Cranking speed is too slow (battery is under charged).
4. The sampling timing of the tester and measured pulse
were not synch ronized. (System is normal if measured
voltage is over the standard voltage at least once.)
5.
Poorly connected connectors or an open circuit in the
ignition system.
6. Faulty ignition coil.
7. Faulty engine control module (ECM) (when above No.1
through 6 are normal).
No peak voltage.
,.
Incorrect peak voltage adaptor connections. (System is
normal if measu red voltage is over the specifications
with reverse connections.)
2.
Battery is undercharged. (l arge voltage drop when the
engine is started.)
3.
Faulty ignition switch or engine stop switch.
4. loose or poorly connected ECM connectors.
5.
No voltage at the Blacklwhite (power source) wire of the
ECM.
6. Open circuit or poor connection in the Green (ground)
wire of the ECM.
7. Faulty peak voltage adaptor.
8.
Faulty ignition pulse generator (Measure peak voltage)
9.
FaultY ECM (when above No.1 through 8 are normal).
Peak voltage is normal, but no spark
,.
Faulty spark plug or leaking ignition coil secondary cur-
jumps at the plug. rent.
2. Faulty ignition coil.
Ignition
low peak voltage.
,.
The multimeter impedance is too low; below 10 MOl
pulse DCV.
generator 2. Cranking speed is too slow (battery is under charged).
3.
The sampling timing of the tester and measured pulse
were not synchronized. (System is normal if measured
voltage is over the standa rd voltage at least once.)
4. Faulty ignition pulse generator (when above No.1
through 3 are normal).
No peak voltage.
,.
Faulty peak voltage adaptor.
2. Faulty ignition pulse generator.
20-4