Yamaha VMX12 2001 Service Manual page 406

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 →
Negative tester probe →
Positive tester probe →
Negative tester probe →
NOTE:
@
When you switch the positive and negative
tester probes, the readings in the above chart
will be reversed.
@
• Are the tester readings correct?
YES
sky blue 1
Continu-
ity
yellow 2
yellow 2
No conti-
nuity
sky blue 1
NO
Replace the diode
assembly.
IGNITION SYSTEM
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?
EAS00754
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.
8 - 14
ELEC
YES
Replace the vacuum
pressure sensor.
YES
Properly connect or
repair the
system's wiring.
– +
NO
NO
ignition