Driver Side Door Key Lock and Unlock Switch Circuit: Description

The driver's door key lock and unlock switch is built into the driver's door lock. When the driver's door key cylinder is turned to lock all the doors using the key, there is continuity between terminals L and E on the key lock and unlock switch When the cylinder is turned to unlock the doors, there is continuity between terminals UL and E. Terminals L2 and UL3 on the main body ECU are connected to the door lock assembly LH, and door lock/unlock request signals (by key) are input to the main body ECU. The main body ECU constantly applies voltage to terminal L on the driver's door lock assembly LH via terminal L2. When the driver's door key cylinder is turned to lock all the doors using the key, current flows from terminal L2 to terminal L. The main body ECU also applies constant voltage to terminal UL of the door lock assembly LH via terminal UL3. When the door key cylinder is turned to unlock the doors using the key, current flows from terminal UL3 to terminal UL.