Normal Operation

WARNING: This page is about a different car, the 2009 Mercury Milan, 2009 Lincoln MKZ, and 2009 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.

The smart junction box (SJB) monitors for a ground signal on the reference circuits CPK29 (GY/BU), CPK30 (VT/GN), and CPK31 (YE/GN) for the keyless entry keypad. When an individual keypad button is pressed, an individual or combination of the reference circuits is routed to ground. The SJB then determines which button was pressed based on which circuit(s) are grounded. The keypad is grounded through circuit GD126 (BK/WH). Once the SJB determines that the 5-digit personal entry code, or the factory set 5-digit entry code has been entered on the keypad, the SJB then energizes the driver door unlock relay to unlock the driver door.

To unlock all the doors, the 3/4 button must be pressed within 5 seconds of the 5-digit code being entered.

To release the luggage compartment lid, the 5/6 button must be pressed within 5 seconds of the 5-digit code being entered.

To lock all the doors, the 5-digit code does not need to be entered. Press the 7/8 and 9/0 buttons at the same time.

DTC B2695 (Keypad_A Switch Circuit Failure) - is an on-demand DTC that sets when the SJB detects a short to ground on the keyless entry keypad switch A circuit CPK29 (GY/BU).
DTC B2696 (Keypad_B Switch Circuit Failure) - is an on-demand DTC that sets when the SJB detects a short to ground on the keyless entry keypad switch B circuit CPK30 (VT/GN).
DTC B2697 (Keypad_C Switch Circuit Failure) - is an on-demand DTC that sets when the SJB detects a short to ground on the keyless entry keypad switch C circuit CPK31 (YE/GN).

This pinpoint test is intended to diagnose the following:

Wiring, terminals or connectors
Keyless entry keypad
SJB