4 Runner 4WD V8-4.7L (2UZ-FE) (2003)
2. Disconnect connector "B" and measure the resistance between the connectors.
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".
c. Check the voltage.
1. In a circuit in which voltage is applied (to the ECU connector terminal), an open circuit can be checked by conducting a voltage check.
As shown in Fig. 4, with each connector still connected, measure the voltage between the body ground and terminal 1 of connector "A" at
the ECU 5 V output terminal, terminal 1 of connector "B", and terminal 1 of connector "C", in that order.
2. If the results are:
5 V: Between terminal 1 of connector "a" and body ground
5 V: between terminal 1 of connector "b" and body ground
0 V: between terminal 1 of connector "c" and body ground
Then it is found out that there is an open circuit in the wire harness between terminal 1 of "B" and terminal 1 of "C".
3. CHECK SHORT CIRCUIT
a. If the wire harness is ground shorted as in Fig. 5, locate the section by conducting a "continuity check with the body ground".