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BF135A•BF150A
5-89
• ECT Sensor 4 Troubleshooting
MIL blinks 27 times
1. Symptom reproduction test
-1. Reset the ECM.
-2. Turn the ignition switch OFF and connect the test har-
ness.
• Hold the sensor connector connected.
-3. Turn the ignition switch ON.
-4. Measure the voltage between the test harness A-6 ter-
minal (+) and the A-2 terminal (–).
Is the voltage 0.08 – 4.99V?
YES –
Temporary failure (Disappeared)
NO –
Perform "2. ECT sensor 4 signal line open cir-
cuit 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 voltage 4.75 – 5.25V?
YES –
Perform "3. ECT sensor 4 signal line short cir-
cuit check".
NO –
Repair open in the wire between the ECT
sensor 4 and the ECM.
3. ECT sensor 4 signal line short circuit check
-1. Turn the ignition switch OFF. Disconnect the ECT sen-
sor 4 connector and the ECM connector B.
-2. Check for the continuity between the No.2 (Red/
Green) terminal of the ECT sensor 4 harness side 2P
connector and the body ground.
Is there the continuity?
YES –
Repair short in the wire between the ECT
sensor 4 and the engine ground.
NO –
Perform “4. ECT sensor 4 ground line open
circuit check”.
4. 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 "5. ECT sensor 4 check".
NO –
Repair open in the wire between the ECT
sensor 4 and the engine ground.
ECT SENSOR 4 HARNESS SIDE
2P CONNECTOR
VIEWED FROM THE TERMINAL SIDE
ECT SENSOR 4 HARNESS SIDE
2P CONNECTOR
VIEWED FROM THE TERMINAL SIDE
A-2
A-6
ECT SENSOR 4 HARNESS
SIDE 2P CONNECTOR
VIEWED FROM THE TERMINAL SIDE
TOH3 (RED/GREEN)
TOH3 (RED/GREEN)
SG2 (GREEN/RED)