Yamaha YZF-R1 1998, Service Manual, Page: 400 / 418

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ELEC
EXUP SYSTEM
EB811010
TROUBLESHOOTING
Procedure 1
Check:
1. Exup servomotor operation
(with the EXUP servomotor coupler
connected to the wire harness)
2. voltage
3. Exup servomotor operation
4. (with the EXUP servomotor coupler
disconnected from the wire harness)
5. Exup servomotor resistance
6. wiring
(the entire EXUP system)
Procedure 2
Check:
1. main and ignition fuses
2. battery
3. main switch
4. engine stop switch
5. wiring
(the entire EXUP system)
NOTE:
• Before troubleshooting, remove the
following part(-s):
1) rider seat
2) fuel tank
3) bottom cowling
• Troubleshoot with the following spe-
cial tool(-s).
When the engine speed changes, the
EXUP servomotor does not operate.
Pocket tester
90890-03112
EB811400
Procedure 1
1.EXUP servomotor operation (with the
EXUP servomotor coupler connected to
the wire harness)
• Disconnect the EXUP cables from the
EXUP servomotor pulley.
• Start the engine and rev it to 2,000 r/min.
NO
YES
• Does the EXUP servomotor pulley turn?
Check that the
EXUP cables are
properly installed.
If OK, check the
EXUP valve and
cables. Refer to
“ENGINE” in chap-
ter 4.
EB811401
YES
NO
2.Voltage
• Connect the pocket tester (DC 20V) to
the EXUP servomotor coupler (wire har-
ness side) as shown.
Tester positive probe
→
black/red 1
Tester negative probe
→
black/yellow 2
• Set the main switch to “ON”.
• Measure the voltage (12V) between
black/red 1 and black/yellow 2 (wire
harness side).
• Is the voltage within specification?
Go to Procedure 2.