Honda BF40D Mode D'emploi page 414

• HO2S TROUBLESHOOTING
DTC 1-4: HO2S is faulty
NOTICE
Use a known-good battery to connect the battery to the
connector terminal and take care not to short the circuit.
1) Symptom reproduction test
a. Turn the combination switch OFF. Disconnect the
HO2S 4P connector
18
b. Clear the DTC (P. 5-12).
• Continue the procedure when the DTC does not
clear.
c. Start the engine and let it run at 3,000 min
for 5 minutes or more under no load.
d. Let the engine idle for 1 minute or more.
e. Check the DTC using the HDS (Dr. H or pocket
tester).
Does the DTC 1-4 appear?
YES - Go to "2) Fuel supply system inspection."
NO - Temporary failure (Disappears).
2) Fuel supply system inspection
• Turn the combination switch OFF and measure the
fuel pressure (P. 5-80).
Is the fuel pressure normal?
YES - Go to "3) HO2S inspection"
NO - Recheck with the normal fuel pressure.
5-19
once and connect it again.
-1 (rpm)
414
3) HO2S inspection
a. Turn the combination switch OFF and disconnect
the HO2S 4P connector
b. Connect the battery positive (+) cable to the sensor
side No.4 (White) terminal and the battery negative
cable (-) to the sensor side No.3 (White) terminal of
the HO2S 4P connector
c. Start the engine and let it run at 3,000 min
for 3 minutes or more under no load.
d. Snap the engine with the engine speed in the range
between the idle speed and 4,000
Measure the voltage between the No.1 (Black)
terminal and No.2 (Gray) terminal of the HO2S
sensor side 4P connector
HO2S 4P CONNECTOR HO2S SIDE
18
O2 (Black)
O2HT (White)
12V BATTERY
VIEWED FROM THE TERMINAL SIDE
Is the voltage 0.6V or more with the throttle fully
open and 0.4V or below with the throttle fully
closed?
YES - Go to "4) HO2S signal line short-circuit
inspection."
NO - Replace the HO2S with a new one and
recheck.
.
18
respectively.
18
(rpm)
-1
500 min (rpm).
-1
.
18
SG3 (Gray)
(White)