Compass Calibration

The compass module has 2 types of auto-calibration; slow-cal and fast-cal. Slow-cal ensures that during normal vehicle operation the compass performs auto-calibration functions to keep the compass sensors in their proper operating range. Whenever the ignition is On and the CMTC receives PCI bus data indicating that engine RPM is greater than zero, auto-calibration is performed continuously.

If the calibration information stored in the compass module memory is not within the normal range after a power-up cycle, the compass will display CAL. The CMTC will enter into the fast-cal mode until calibration is complete.

To enter the compass into Manual Calibration mode, perform the following steps:

• Drive the vehicle to an area away from any large metal objects or overhead power lines.
• Ensure that the proper variance zone is selected. See "Setting Magnetic Zone Variance."
• The ignition switch must be in the On position and the CMTC display must not be blank.
• Press the C/T button to view the Compass/Temperature display.
• Press and hold the RESET button until CAL is displayed, then release the button.
• Drive slowly, less than 5 MPH (8 KPH) in at least 1 complete 360-degree circle.
• CAL will remain illuminated to alert the driver that the compass is in the calibration mode.
• After calibration is complete, CAL will turn off.

If the compass appears blank, unable to be calibrated, or the compass displays false indications, the vehicle must be demagnetized. Refer to Compass Demagnetizing Procedure.