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 Instrument Panel Cluster (IPC) receives the key-in-ignition warning status from the Smart Junction Box (SJB) over the Medium Speed Controller Area Network (MS-CAN) communication bus.

The key-in-ignition warning switch (part of the ignition switch) is hardwired to the SJB through the key-in-ignition input circuit. When the key is inserted into the ignition lock cylinder, the key-in-ignition switch closes and supplies voltage to the SJB .

The SJB monitors the door ajar input from the LH front door and the key-in-ignition switch status. When the SJB detects a key-in-ignition voltage and the LH front door is open or ajar, the SJB sends the IPC a chime request message to sound the key-in-ignition warning chime.

DTC B1352 (Ignition Key-In Circuit Failure) - an on-demand DTC that sets in the SJB if the SJB detects an open on the key-in-ignition switch input circuit or if the SJB detects ignition START, RUN/START or RUN/ACC inputs without the key-in-ignition input.

This pinpoint test is intended to diagnose the following:

Wiring, terminals or connectors
Key-in-ignition switch (part of the ignition switch)
SJB
IPC