HONDA marine BF135A, Руководство по ремонту, Страница: 48 / 49

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DTC 143-2: ECT sensor 4 voltage is high
1. Symptom reproduction test
-1. Connect the Dr. H and clear the DTC once. If the
DTC can not be cleared, go on the troubleshooting.
-2. Turn the ignition switch ON.
-3. Measure the ECT sensor 4 voltage using the Dr. H.
Is the measured voltage 0.08 – 4.99V?
YES – Temporary failure (Disappeared)
NO – Perform “2. ECT sensor 4 signal line open
circuit check”.
2. ECT sensor 4 signal line open circuit check
-1. Turn the ignition switch OFF and disconnect the 2P
connector from the ECT sensor 4.
-2. Turn the ignition switch ON.
-3. Measure the voltage between the No. 2 (Red/Green)
terminal of the ECT sensor 4 harness side 2P con-
nector and the engine ground.
Is the measured voltage 4.75 – 5.25V?
YES – Perform “3. ECT sensor 4 ground line open
circuit check”.
NO – Repair open in the wire between the ECT
sensor 4 and the ECM.
3. ECT sensor 4 ground line open circuit check
-1. Connect the ECM connector B.
-2. Check for the continuity between the No. 1
(Green/Red) terminal of the ECT sensor 4 harness
side 2P connector and the body ground.
Is there the continuity?
YES – Perform “4. ECT sensor 4 check”.
NO – Repair open in the wire between the ECT
sensor 4 and the engine ground.
4. ECT sensor 4 check
-1. Turn the ignition switch OFF and connect all the con-
nectors.
-2. Turn the ignition switch ON and measure the ECT
sensor 4 temperature using the Dr. H.
Does the measurement correspond to the engine
coolant temperature?
YES – When the DTC appears again, substitute a
known-good ECM and recheck.
NO – Replace the ECT sensor 4.
ECT SENSOR 4 HARNESS
SIDE 2P CONNECTOR
VIEWED FROM THE
TERMINAL SIDE
TOH3
(RED/GREEN)
ECT SENSOR 4 HARNESS SIDE
2P CONNECTOR
VIEWED FROM THE
TERMINAL SIDE
SG2
(GREEN/RED)