Normal Operation
WARNING: This page is about a different car, the 2009 Ford Mustang. However, it is still accessible from the selected car via links, so may be relevant.
The ignition switch receives fused battery voltage from Bussed Electrical Center (BEC) fuse 68 (20A) along circuit 1050 (LG/VT), this voltage is then sent to the Smart Junction Box (SJB) for various systems depending on the ignition switch position. The ignition switch has 4 possible positions:
- OFF, there is no voltage sent to the SJB, but voltage is sent to the instrument cluster for the key-in ignition system. Refer to INSTRUMENT CLUSTER (IC), MESSAGE CENTER, AND WARNING CHIMES article to diagnose any key-in ignition concerns.
- ACC, the voltage is sent to the SJB along circuit 1002 (PK/BK).
- RUN, the voltage is sent to the SJB along circuit 1044 (WH/YE).
- START, the voltage is sent to the SJB along circuit 1522 (DG).
This pinpoint test is intended to diagnose the following:
- Fuse(s)
- Wiring, terminals or connectors
- Ignition switch
- BEC
- SJB