Normal Operation
WARNING: This page is about a different car, the 2007 Mercury Mariner and 2007 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
The smart junction box (SJB) sends voltage reference signals to the keyless entry keypad through circuits 78 (LB/YE), 79 (LG/RD), 121 (YE/BK). When the buttons are pressed on the keypad, one or more of the signals are routed to ground through circuit 570 (BK/WH). Depending on the signals received, the SJB is able to determine which button is pressed. When a correct code has been entered, the SJB operates the locks accordingly.
Possible Causes
- Circuit 78 (LB/YE) open or short to ground
- Circuit 79 (LG/RD) open or short to ground
- Circuit 121 (YE/BK) open or short to ground
- Circuit 570 (BK/WH) open
- Keyless entry keypad
- SJB