Grand Cherokee 2WD Limited V8-4.7L (2002)
compass readings to be erroneous for a continuous period of five (5) minutes. During fast Auto-Cal, CAL will be displayed along with the
temperature.
Fast Auto-Cal can also be performed manually, by pressing and holding the get he RESET button for 10 seconds during the Compass/Temperature
display mode.
Setting Magnetic Zone Variance
Variance is the difference between magnetic North and geographic North. For proper compass function, the correct variance zone must be set.
Refer to the Zone Variance map for the correct zone. Follow these steps to check or change the variance zone:
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The ignition switch must be in the ON position and the EVIC display must not be blank.
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If the compass/temperature data is not currently being displayed, momentarily press and release the C/T button to display compass/temp
information.
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Press and hold the RESET button until VARIANCE = XX is displayed. The EVIC will display the variance zone stored in memory and the
word VARIANCE.
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Use the STEP button to select the proper variance zone number, 1 through 15.
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After selecting the proper zone number, momentarily press and release the RESET button. The variance zone is then stored in the memory and
the EVIC returns to normal operation.
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 EVIC
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 EVIC will enter into the fast-cal mode until calibration is complete.
To enter the compass into Manual Calibration mode, perform the following steps:
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Drive the vehicle to an area away from any large metal objects or overhead power lines.
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Ensure that the proper variance zone is selected. See "Setting Magnetic Zone Variance."
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The ignition switch must be in the ON position and the EVIC display must not be blank.
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Press the C/T button to view the Compass/ Temperature display.
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Press and hold the RESET button until CAL is displayed, then release the button.
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Drive slowly, less than 5 mph (8 km/h) in at least 1 complete 360 degree circle.
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CAL will remain illuminated to alert the driver that the compass is in the calibration mode.
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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.
Diagnosis and Testing
Self-Check Diagnostics
The EVIC is capable of performing a diagnostic self check on its internal functions. EVIC diagnostics may be performed using a DRB III( or by
using the following procedure:
1. With the ignition switch in the OFF position, depress and hold the RESET and the C/T buttons.
