Yamaha VMX12 2001, Service Manual

Page: 406 / 454

8 - 14
– +
ELEC
IGNITION SYSTEM
YES NO
YES
NO
EAS00754
YES
NO
12.Diode assembly
• Disconnect the diode assembly coupler
from the wire harness.
• Connect the pocket tester (
Ω ×
1) to the
diode assembly coupler as shown.
• Check the diode assembly for continuity.
Positive tester probe
→
sky blue
1
Negative tester probe
→
yellow
2
Continu-
ity
Positive tester probe
→
yellow
2
Negative tester probe
→
sky blue
1
No conti-
nuity
NOTE:
@
When you switch the positive and negative
tester probes, the readings in the above chart
will be reversed.
@
• Are the tester readings correct?
Replace the diode
assembly.
13.Vacuum pressure sensor
• Disconnect the vacuum pressure sensor
coupler from the wire harness.
• Connect the pocket tester (DC 20 V) and
battery (12 V) to the vacuum pressure sen-
sor terminals as shown.
Battery positive terminal
→
red/black
1
Battery negative terminal
→
black/yellow
2
Tester positive probe
→
black/red
3
Tester negative probe
→
black/yellow
2
• Measure the vacuum pressure sensor out-
put voltage.
Vacuum pressure sensor out put
voltage
2.0 V at 0 Pa (0 bar)
• Is the vacuum pressure sensor OK?
Replace the vacuum
pressure sensor.
14.Wiring connections
• Check the entire ignition system’s wiring.
Refer to “CIRCUIT DIAGRAM”.
• Is the ignition system’s wiring properly con-
nected and without defects?
Replace the ignitor
unit. Properly connect or
repair the ignition
system’s wiring.