Honda BF40D Mode D'emploi page 415

4) HO2S signal line short-circuit inspection
a. Turn the combination switch OFF and disconnect
the battery.
b. Disconnect the ECM connector B
continuity between the HO2S 4P connector
main wire harness side No.1 (Black/Yellow)
terminal and the engine ground.
HO2S 4P CONNECTOR
MAIN WIRE HARNESS SIDE
18
VIEWED FROM THE TERMINAL SIDE
Is there continuity?
YES - Repair short in the main wire harness
between the ECM and the HO2S.
NO - Go to "5) HO2S signal line open-circuit
inspection."
5) HO2S signal line open-circuit inspection
• Check for continuity between the HO2S 4P connector
main wire harness side No.1 (Black/Yellow)
18
terminal and the ECM connector B
harness side No.30 (Black/Yellow) terminal.
ECM CONNECTOR B
MAIN WIRE HARNESS SIDE
10
O2 (Black/Yellow)
18
HO2S 4P CONNECTOR
MAIN WIRE HARNESS SIDE
Is there continuity?
YES - Go to "6) HO2S GND line open-circuit
inspection."
NO - Repair open in the main wire harness
between the ECM and the HO2S.
. Check for
10
18
O2 (Black/Yellow)
main wire
10
VIEWED FROM THE
TERMINAL SIDE
415
6) HO2S GND line open-circuit inspection
• Connect the ECM connector B
continuity between the HO2S 4P connector
main wire harness side No.2 (Green/Red) terminal
and the engine ground.
HO2S 4P CONNECTOR
MAIN WIRE HARNESS SIDE
18
SG3
(Green/Red)
VIEWED FROM THE TERMINAL SIDE
Is there continuity?
YES - Replace the ECM with a new one and
recheck.
NO - Repair open in the main wire harness
between the ECM and the HO2S.
. Check for
10
18
5-20