TOHATSU BFT115A Service Manual page 196

FUEL SYSTEM
2. A/F sensor line open or short circuit inspection
Turn the combination switch OFF.
Disconnect the A/F sensor 4P connector
ECM connector A
Check for open or short circuit between the A/F
sensor 4P connector
No.1 (Black/Yellow) terminal and ECM connector A
12
terminal.
Check for open or short circuit between the A/F
sensor 4P connector
No.2 (White/Black) terminal and ECM connector A
12
terminal.
Is the A/F sensor line open or short?
YES
NO
5-78
.
12
main wire harness side
3
main wire harness side No.27 (Black/Yellow)
main wire harness side
3
main wire harness side No.28 (White/Black)
– Repair open or short in the Black/Yellow
wire or White/Black wire.
– Replace the A/F sensor with a new one
and recheck. If the A/F sensor is replaced,
but MIL blinks 48, replace the ECM with a
new one and recheck.
and
3