BF135A•BF150A
5-33
• ECT Sensor 1 Troubleshooting
DTC 6-1: ECT sensor 1 voltage is low
1. Symptom reproduction test
-1. Connect the HDS pocket tester and clear the DTC
once. If the DTC can not be cleared, go on the trou-
bleshooting.
-2. Turn the ignition switch ON.
-3. Check the ECT sensor 1 voltage using the HDS pock-
et tester.
Is the measurement 0.23 – 3.15V?
YES –
Temporary failure (Disappeared)
NO –
Perform “2. ECT sensor 1 line short circuit
check”.
2. ECT sensor 1 line short circuit check
-1. Turn the ignition switch OFF and disconnect the ECM
connector B.
-2. Check for the continuity between the No. 2 (Red/White)
terminal of the ECT sensor 1 harness side 2P con-
nector and the body ground.
Is there the continuity?
YES –
Repair short in the wire between the ECM
and the ECT sensor 1.
NO –
Perform “3. ECT sensor 1 check”.
3. ECT sensor 1 check
-1. Turn the ignition switch OFF and connect the HDS
pocket tester.
-2. Turn the ignition switch ON. Check the engine coolant
temperature with the HDS pocket tester.
Is the engine coolant temperature normal?
YES –
Substitute a known–good ECM and recheck.
NO –
Replace the ECT sensor 1 and recheck.
DTC 6-2: ECT sensor 1 voltage is high
1. Symptom reproduction test
-1. Connect the HDS pocket tester and clear the DTC
once. If the DTC can not be cleared, go on the trou-
bleshooting.
-2. Turn the ignition switch ON.
-3. Measure the ECT sensor 1 voltage using the HDS
pocket tester.
Is the measurement 0.23 – 3.15V?
YES –
Temporary failure (Disappeared)
NO –
Go to the step 2.
2. ECT sensor 1 line check
-1. Turn the ignition switch OFF and disconnect the ECT
sensor 1 connector.
-2. Turn the ignition switch ON. Measure the voltage
between the No. 2 (Red/White) and the No. 1
(Green/Red) terminals of the ECT sensor 1 harness
side 2P connector.
Is the measurement 4.30 – 5.25V?
YES –
Perform “4. ECT sensor 1 check”.
NO –
Perform “3. ECT sensor 1 signal line open cir-
cuit check”.
3. ECT sensor 1 line open circuit check
-1. Turn the ignition switch ON. Measure the voltage
between the No. 2 (Red/White) terminal of the ECT
sensor 1 harness side 2P connector and the engine
ground.
ECT SENSOR 1 HARNESS
SIDE 2P CONNECTOR
TE (RED/WHITE)
VIEWED FROM THE
TERMINAL SIDE
ECT SENSOR 1 HARNESS
SIDE 2P CONNECTOR
VIEWED FROM THE
TERMINAL SIDE
SG2
(GREEN/RED)
TE (RED/WHITE)
ECT SENSOR 1 HARNESS
SIDE 2P CONNECTOR
VIEWED FROM THE
TERMINAL SIDE
TE (RED/WHIT)