TOHATSU BFT250A Service Manual page 158

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FUEL SYSTEM
DTC 23-1 (ABNORMAL OUTPUT OF KNOCK SENSOR)
ECM
1. Symptom reproduction test
Turn the combination switch OFF.
Disconnect the knock sensor 1P connector
ECM connector B
Clear the DTC (page 5-6).
• Continue the procedure if the DTC does not
clear.
Start the engine and let it run at 3,000 min
5 minutes or more under no load until the engine
temperature is over 85 °C (185 °F).
Lower the engine speed gradually and run it at
3,000 – 4,000 min
Recheck the DTC with the HDS.
Does the DTC 23-1 appear?
YES
NO
2. Knock sensor line open or short circuit
inspection
Turn the combination switch OFF.
Disconnect the knock sensor 1P connector
and ECM connector B
Check the open and short in wire between the
Knock sensor and ECM.
Is the knock sensor line correct?
YES
NO
5-36
KS R/Bu
, switch wire 6P connector
and then reconnect them.
-1
(rpm) for 10 seconds.
– GO TO STEP 2.
– Temporary failure
reappear).
.
– GO TO STEP 3.
– Repair open or short in the main wire
harness between the ECM and knock
sensor.
R/Bu R/Bu
,
-1
(rpm) for
(code does not
KNOCK
SENSOR
R/Bu
Bl: Black Br: Brown
Y: Yellow O: Orange
Bu: Blue Lb: Light blue
G: Green Lg: Light green
R: Red P: Pink
W: White Gr: Gray