Ford ST3093-A - Special Tool(s)

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DIAGNOSIS AND TESTING

Electronic Compass

Special Tool(s)

Fluke 77-IV Digital Multimeter

FLU77-4 or equivalent

Vehicle Communication Module (VCM) and Integrated Diagnostic System (IDS) software

with appropriate hardware, or equivalent scan tool

Flex Probe Kit

105-R025D or equivalent

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 Section 415-00.

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.

Inspection and Verification

1. Verify the customer concern.

2. Visually inspect for obvious signs of mechanical or electrical damage.

Visual Inspection Chart

Mechanical Electrical

• Compass module (integral to the auto-dimming interior mirror)

• Front Display Interface Module (FDIM)

• Smart Junction Box (SJB) fuse(s):

— 14 (10A) (FDIM)

— 41 (15A) (compass module)

• Wiring, terminals or connectors