TOHATSU BFT115A Service Manual page 161

6. A/F sensor line short circuit inspection
Disconnect the ECM connector A
Check for continuity
terminals.
– A/F sensor 4P connector
harness side No.1 (Black/yellow) terminal and
ECM connector A
12
No.18 (Black/White) terminal
– A/F sensor 4P connector
harness side No.2 (White/Black) terminal and
ECM connector A
12
No.18 (Black/White) terminal
– A/F sensor 4P connector
harness side No.1 (Black/yellow) terminal and
ECM connector A
12
No.36 (White) terminal
– A/F sensor 4P connector
harness side No.2 (White/Black) terminal and
ECM connector A
12
No.36 (White) terminal
Is there continuity?
YES – • Repair short in the Black/yellow wire
and Black/White wire between the ECM
and A/F sensor.
• Repair short in the White/Black wire
and Black/White wire between the ECM
and A/F sensor.
• Repair short in the Black/yellow wire
and White wire between the ECM and
A/F sensor.
• Repair short in the White/Black wire
and White wire between the ECM and
A/F sensor.
NO – • Repair open in the White wire between
the fuse/relay junction box and A/F
sensor.
• Repair open in the White wire between
the ECM and fuse/relay junction box.
• Repair open or short in the Black/White
wire between the ECM and A/F sensor.
• Repair open or short in the Green/
Yellow wire between the ECM and
fuse/relay junction box.
• If the wire harness is normal, replace
the A/F sensor with a new one and
recheck.
• If the A/F sensor is replaced, but DTC
41-4 still appears, replace the ECM
with a new one and recheck.
.
12
between the following
main wire
3
main wire harness side
main wire
3
main wire harness side
main wire
3
main wire harness side
main wire
3
main wire harness side
FUEL SYSTEM
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