Electrical Compass - Electronic Compass: Overview Lincoln MKS I

Principles of Operation

Note. The Smart Junction Box (SJB) is also known as the Generic Electronic Module (GEM).

Note. This procedure is only applicable to vehicles without navigation. For vehicles with navigation, refer to INFORMATION AND ENTERTAINMENT SYSTEMS .

The compass display (located in the Front Display Interface Module (FDIM)) receives battery voltage from the SJB . The compass module (integral to the auto-dimming interior mirror) provides hardwired vehicle directional inputs to the Instrument Panel Cluster (IPC), which sends the compass information to the FDIM over the Medium Speed Controller Area Network (MS-CAN). The compass is capable of self-calibrating. This decreases the need to manually set the compass. If the compass is displaying a heading (and not displaying the C or CAL indicator), the compass is in auto-calibration mode. In this mode, the compass automatically calibrates for changes in vehicle magnetics over the life of the vehicle. This auto-calibration mode makes sure the compass heading is always accurate. If the compass displays the C or CAL indicator for an extended period of time (longer than 5 seconds), this indicates the compass has been placed in the manual calibration mode and therefore, requires manual calibration.

Normal Operation

The compass display (located in the Front Display Interface Module (FDIM)) receives battery voltage from the Smart Junction Box (SJB) fuse 14 (10A) through circuit SBP14. Ground for the FDIM is supplied through circuit GD114. The compass module (integral to the auto-dimming interior mirror) provides vehicle directional inputs over circuits VMC31 and VMC30 to the Instrument Panel Cluster (IPC), which sends the compass information to the FDIM over the Medium Speed Controller Area Network (MS-CAN). The FDIM displays the compass direction according to the information that has been provided by the compass module to the IPC .

1. DTC U0161:00 (Lost Communication With Compass Module: No Sub Type Information) - sets when the IPC does not receive any communication from the compass module for 5 seconds or longer.
2. DTC U0462:68 (Invalid Data Received From Compass Module: Event Information) - sets when the IPC attempts a self-test of the compass module and its associated circuits and a failure results.

This pinpoint test is intended to diagnose the following

1. Fuse(s)
2. Wiring, terminals or connectors
3. Compass module (integral to the auto-dimming interior mirror)
4. FDIM (compass display)
5. IPC

The compass module (integral to the auto-dimming interior mirror) provides vehicle directional inputs over circuits VMC31 and VMC30 to the Instrument Panel Cluster (IPC), which sends the compass information to the Front Display Interface Module (FDIM) (compass display) over the Medium Speed Controller Area Network (MS-CAN). The FDIM displays the compass direction according to the information that has been provided by the compass module to the IPC .

This pinpoint test is intended to diagnose the following

1. Compass zone setting
2. Compass calibration
3. Compass module (integral to the auto-dimming interior mirror)