FI7187
Z17004
C
B
A
OPEN
Sensor
Fig. 1
ECU
1
2
1
2
1
2
2
1
Z17005
Fig. 2
Sensor
ECU
C
B
A
1
2
1
2
1
2
Z17807
Fig. 3
Sensor
ECU
C
A
1
2
1
2
1
2
2
1
B2
B1
--
INTRODUCTION
HOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
IN--23
5 . CO NNE CTO R HANDLI NG
When inserting tester probes into a connector, insert them from
the rear of the connector. When necessary, use mini test leads.
For water resistant connectors which cannot be accessed from
behind, take good care not to deform the connector terminals.
6 . CHE CK O P E N CI RCUI T
For the open circuit in the wire harness in Fig.1, perform ”(a)
Continuity Check” or ”(b) Voltage Check” to locate the section.
(a)
Check the continuity.
(1)
Disconnect connectors ”A” and ”C” and measure
the resistance between them.
In the case of Fig.2,
Between terminal 1 of connector ”A” and terminal 1
of connector ”C”
→
No continuity (open)
Between terminal 2 of connector ”A” and terminal 2
of connector ”C”
→
Continuity
Therefore, it is found out that there is an open circuit
between terminal 1 of connector ”A” and terminal 1
of connector ”C”.
(2)
Disconnect connector ”B” and measure the resis-
tance between them.
In the case of Fig.3,
Between terminal 1 of connector ”A” and terminal 1
of connector ”B1”
→
Continuity
Between terminal 1 of connector ”B2” and terminal
1 of connector ”C”
→
No continuity (open)
Therefore, it is found out that there is an open circuit
between terminal 1 of connector ”B2” and terminal
1 of connector ”C”.
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3RZ-F,3RZ-FE
