Yaris L4-15L (1NZ-FE) (2007) | Lighting and Horns | Courtesy Lamp
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. 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 the results match the examples, an open circuit exists in the wire harness between terminal 1 of connector B and terminal 1 of connector C.
Check For Short Circuit
CHECK FOR SHORT CIRCUIT
a. If the wire harness is ground shorted (Fig. 5), locate the section by conducting a resistance check with the body ground.
b. Check the resistance with the body ground.
1. Disconnect connectors A and C and measure the resistance.