FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM: Car repair manuals for everyone.

Pinpoint Tests AF: The Compass Is Inaccurate




Instrumentation, Message Center and Warning Chimes

Pinpoint Test

Pinpoint Test AF: The Compass Is Inaccurate


Normal Operation

The auto-dimming interior mirror communicates the vehicle direction to the Instrument Cluster (IC) through the compass communication data plus circuit VMC31 (GY/BU) and compass communication data minus circuit VMC30 (BU/GY). The magnetic fields generated by the earths 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. The compass zone must be set 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 compass module to compensate for vehicle factors that influence the accuracy of the compass.

This pinpoint test is intended to diagnose the following:

- Zone setting
- Calibration
- Auto-dimming interior mirror



PINPOINT TEST AF: THE COMPASS IS INACCURATE

-------------------------------------------------
AF1 CHECK COMPASS ACCURACY


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





- Does the compass display as indicated?

Yes
The compass is OK.

No
GO to AF2.

-------------------------------------------------
AF2 CHECK THE COMPASS ZONE SETTING AND CALIBRATION


- Set the zone. Refer to Compass Zone Adjustment Compass Zone Adjustment.
- Calibrate the compass. Refer to Compass Calibration Compass Calibration.
- Does the compass calibrate correctly?

Yes
The compass is OK. The concern may have been caused by an incorrect zone setting or the compass was out of calibration.

No
INSTALL a new auto-dimming interior mirror. REFER to Mirrors. SET the zone. REFER to Compass Zone Adjustment Compass Zone Adjustment.
CALIBRATE the compass. REFER to Compass Calibration Compass Calibration. TEST the system for normal operation.

-------------------------------------------------