TOHATSU BFT 250A, Service Manual

Page: 162 / 639

5-40
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FUEL SYSTEM
DTC 140-1, 140-2 (ECT SENSOR 2 (EMT SENSOR 1) VOLTAGE IS TOO LOW
OR TOO HIGH)
DTC 140-1 (ECT SENSOR 2 (EMT SENSOR 1)
VOLTAGE IS TOO LOW)
1. Symptom reproduction test
Turn the combination switch OFF.
Disconnect the EMT sensor 1 2P connector
,
ECM connector A , ECM connector B ,
joint connector 1 and then reconnect them.
Clear the DTC (page 5-6).
• Continue the procedure if the DTC does not
clear.
Turn the combination switch ON.
Measure the EMT sensor 1 voltage using the HDS.
Is the measurement within 0.08 – 4.92 V?
YES – Temporary failure (code does not
reappear).
NO – GO TO STEP 2.
2. EMT sensor 1 signal line short circuit inspection
Turn the combination switch OFF and disconnect
the EMT sensor 1 2P connector
.
Turn the combination switch ON.
Measure the voltage between the EMT sensor 1 2P
connector
main wire harness side No.1 (Red/
Black) terminal and engine ground.
Is the measurement within 4.75 – 5.25 V?
YES – Replace the EMT sensor 1 with a new one
and recheck.
NO – Repair short in the main wire harness
between the ECM and EMT sensor 1. If
the main wire is correct, replace the ECM
with a new one and recheck.
Bl: Black
Y: Yellow
Bu: Blue
G: Green
R: Red
W: White Br: Brown
O: Orange
Lb: Light blue
Lg: Light green
P: Pink
Gr: Gray
ECM
ECT SENSOR
(EMT SENSOR 1)
25
TOH1 R/Bl
1
R/Bl
5 V
SG2
22
G
9
G
2
JOINT CONNECTOR 1
3
EMT SENSOR 1 2P CONNECTOR
MAIN WIRE HARNESS SIDE
TOH1
(Red/Black)