Normal Operation

WARNING: This page is about a different car, the 2010 Mercury Milan, 2010 Lincoln MKZ, and 2010 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 keyless entry keypad signal input circuits. When an individual keypad button is pressed, an individual or combination of the input circuits is routed to ground. The SJB then determines which button was pressed based on which circuit(s) are grounded. The keypad has a dedicated ground circuit. 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 B2A26 (Keypad Switch Circuit Failure) - an on-demand DTC that sets when the SJB detects a short to ground on any of the keyless entry keypad input circuits.

This pinpoint test is intended to diagnose the following:

Wiring, terminals or connectors
Keyless entry keypad
SJB