Yanmar BY Series Service Manual page 242

Component Tests
Main Relay (K2)
12 V is supplied directly to terminal 30. An internal
connection connects one end of the winding to
terminal 30. When the key switch is turned ON, a
12 V signal is sent to ECU terminal 2/7. The ECU
then completes the winding ground circuit (terminal
85) through ECU terminal 2/20.
Results of Failed Relay
Failure of the relay results in:
• Loss of power to all systems
If this relay is defective, the following P-codes may
be generated.
• P0689 - short circuit to ground
• P0690 - short circuit to B+
Note: Viewed from bottom of connector.
Figure 12-7
1 – Pin 2 - terminal 87
2 – Pin 4 - terminal 85
3 – Pin 5 - terminal 87
4 – Pin 6 - terminal 30
BY Service Manual
0004173
ELECTRICAL AND ECU
Fuel Pump Relay (K3)
12 V is supplied by fuse F3 to terminal 30. An
internal connection connects one end of the
winding to terminal 30. When the key switch is
turned ON, a 12 V signal is sent to ECU terminal
2/7. The ECU then completes the winding ground
circuit (terminal 85) through ECU terminal 2/32.
Results of Failed Relay
Failure of the relay results in:
• Fuel supply pump will not operate
If this relay is defective, the following P-codes may
be generated.
• P0230 - power interruption - defective fuse (F5) or
relay or connections
• P0231 - regulation short circuit to B-
• P0232 - regulation short circuit to B+
Note: Viewed from bottom of connector.
Figure 12-8
1 – Pin 2 - terminal 87
2 – Pin 4 - terminal 85
3 – Pin 5 - terminal 87 (not used)
4 – Pin 6 - terminal 30
0004173
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