Toyota Corolla (E120): Circuit description

The key unlock warning switch comes on when the ignition key is inserted in the key cylinder and goes off when the ignition key is removed.

Wiring diagram

Inspection procedure

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    Inspection procedure
    1 Check relay (marking: starter cut) Inspect the relay continuity, as shown in the illustration and table. Standard: 2 Check tvip ecu Disconnect the tvip ecu connector.  turn the ignition switch position to the start.  measure the voltage between the termina ...

    Circuit description
    Refer to dtc p0130 Hint: the ecm provides a pulse width modulated control circuit to adjust current through the heater. The heated oxygen sensor heater circuit uses a relay on the b+ side of the circuit. Monitor description The ecm uses the heated oxygen sensor information to regulate t ...

    How to proceed with troubleshooting
    The hand–held tester can be used at step 4, 6, 8 and 9. 1 Vehicle brought to workshop 2 Customer problem analysis 3 Warning light check 4 The dtcs check (present and past dtcs) 5 The dtcs chart 6 Circuit inspection 7 Repair 8 Clear the dtcs (present and past dtcs) 9 The dt ...