Tundra 2WD V6-4.0L (1GR-FE) (2005)
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 -> Below 1 Ohms
Between terminal 1 of connector B2 and terminal 1 of connector C -> 10 kOhms or higher (open)
An open circuit exists in the wire harness between terminal 1 of B2 and terminal 1 of C.
b. Check the voltage.
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 body ground and terminal 1 of connector A at the ECU
5V output terminal, terminal 1 of connector B, and terminal 1 of connector C (in that order).
Example results:
5V: Between Terminal 1 of connector A and Body Ground
5V: Between Terminal 1 of connector B and Body Ground
0V: Between Terminal 1 of connector C and Body Ground
In the above example, an open circuit is in the wire harness between terminal 1 of B and terminal 1 of C.
7. CHECK SHORT CIRCUIT
If the wire harness is shorted (Fig. 5), locate the section by conducting a resistance check with ground below.