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) contains several inputs that monitor the voltage outputs from the ignition switch. The SJB uses these inputs to determine the ignition switch position and then sends that information to various modules over the High Speed Controller Area Network (HS-CAN) bus. The ignition switch is designed so that only one output (ACC, RUN or START) is sent to the SJB at a time.
- DTC B2844 (Ignition Fault) - If the SJB receives an invalid ignition RUN input or cannot receive the ignition RUN input during normal operation, DTC B2844 is set.
- DTC U2472 (Unexpected Ignition State) - If the SJB does not receive the ignition RUN signal or receives conflicting ignition switch signals while performing an on-demand self test, DTC U2472 is set.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Ignition switch
- SJB