Diesel Data: Automotive Repair

Pinpoint Test AG: The Compass Is Inaccurate (Without SYNC(R))




Instrumentation, Message Center and Warning Chimes

Pinpoint Test AG: The Compass Is Inaccurate (Without SYNC(R))

Normal Operation

The Instrument Panel Cluster (IPC) receives the compass display message from the Body Control Module (BCM) over the High Speed Controller Area Network (HS-CAN). The BCM (Body Control Module) receives the compass display message from the auto-dimming interior mirror over the Local Interconnect Network (LIN). The BCM (Body Control Module) is only a gateway for the compass information and does not control the compass display. The auto-dimming interior mirror receives voltage from the BCM (Body Control Module) fuse 32 (15A). The magnetic fields generated by the earth's north and south poles are divided into zones that differ from each other with respect to how the magnetic fields appear. The magnetic north can change by up to 4 degrees between zones and become noticeable across multiple zones. Set the compass zone to the correct zone for the compass to read accurately. Factors within the vehicle may affect the ability of the compass module to accurately read the magnetic north. Calibrating the compass allows the auto-dimming interior mirror to compensate for vehicle factors that influence the accuracy of the compass.

NOTE: Outside factors such as bridges, steel structures, tall buildings and power lines also affect compass accuracy.

This pinpoint test is intended to diagnose the following:

- Zone setting

- Calibration

- Auto-dimming interior mirror

PINPOINT TEST AG : THE COMPASS IS INACCURATE (WITHOUT SYNC(R))

AG1 CHECK THE COMPASS ACCURACY

- Position the vehicle and observe the compass display as follows:

Direction Compass Display North N Northeast NE East E Southeast SE South S Southwest SW West W Northwest NW

Does the compass display as indicated?

Yes
The compass is operating correctly at this time.

No
GO to AG2.

AG2 CHECK THE COMPASS ZONE SETTING AND CALIBRATION

- Set the zone. Refer to Compass Zone Adjustment .

- Calibrate the compass. Refer to Compass Calibration .

Does the compass calibrate correctly?

Yes
The compass is OK. The concern may have been cause by an incorrect zone setting or calibration concern.

No
INSTALL a new auto-dimming interior mirror. TEST the system for normal operation.

SET the zone. REFER to Compass Zone Adjustment . CALIBRATE the compass. REFER to Compass Calibration . CLEAR the DTCs. REPEAT the self-test.