Check For Open Circuits

CHECK FOR OPEN CIRCUITS




a. For an open circuit in the wire harness in Fig. 1, perform a resistance check (step b) or a voltage check (step c).
b. Check the resistance.







1. Disconnect connectors A and C, and measure the resistance between them.

HINT: Measure the resistance while lightly shaking the wire harness vertically and horizontally. If your 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.

If your results match the examples above, an open circuit exists 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.

Fig. 4: 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.

If your 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.