Check for open circuit

1. 1
   For an open circuit in the wire harness in fig. 1, Check the resistance or voltage, as described below.
2. 2
   Check the resistance.

   

1. Disconnect connectors a and c, and measure the resistance between them.

Standard resistance (fig. 2) Hint:

Measure the resistance while lightly shaking the wire harness vertically and horizontally.

If the results match the examples above, an open circuit exists between terminal 1 of connector a and terminal 1 of connector c.

2. Disconnect connector b and measure the resistance between the connectors.

Standard resistance (fig. 3)

If the results match the examples
above, an open circuit exists between terminal 1 of connector b2 and terminal 1 of connector c.

3. 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.

With each connector still connected, measure the voltage between the body ground and these terminals (in this order): 1) terminal 1 of connector a, 2) terminal 1 of connector b, and 3) terminal 1 of connector c. Standard voltage (fig. 4)

If the results match the examples
above, an open circuit exists in the wire harness between terminal 1 of connector b and terminal 1 of connector c.