Chrysler PT Cruiser Service & Repair Manual page 458

8M - 2 MESSAGE SYSTEMS
OVERHEAD CONSOLE (Continued)
• Compass/Temperature displayed in Celsius
To put the compass/temperature in the F° display,
press the STEP button once. To put the compass/tem-
perature in the C° display, press the STEP button
twice. A third press of the STEP button will return it
to the blank display.
The overhead console reading and courtesy lamps
operate on battery current that is provided at all
times, regardless of the ignition switch position. The
ground feed for the lamps is switched through the
integral reading and courtesy lamp switches or
through the door jamb switches.
All reading and courtesy lamps located in the over-
head console are activated by the door jamb switches.
When all of the doors are closed, these lamps can be
individually activated by depressing the correspond-
ing lens. When any door is open, depressing the lamp
lenses to activate the lamp switches will not turn the
lamps off.
Each light is turned ON by pressing the lens. Press
the lens a second time to turn the light OFF. The
lights also come ON when a door is opened or the
dimmer switch is turned fully upward, past the sec-
ond detent.
NOTE: The lights will remain ON until the switch is
pressed a second time, so be sure they have been
turned OFF before leaving the vehicle. They will not
turn OFF automatically.
AUTOMATIC COMPASS CALIBRATION
The self calibrating feature of the compass elimi-
nates the need to calibrate the compass for normal
conditions. After approximately 10 ignition cycles the
CAL light will turn ON. The CAL symbol may also
appear after the vehicle is subjected to a high level of
magnetism. After completing three 360° (degree) cir-
cles in an area free from large metal or metallic
objects, the CAL symbol will turn off and the com-
pass will function normally.
MANUAL COMPASS CALIBRATION
If the compass appears to be in the locked up posi-
tion, you may calibrate the compass. Find an open
area away from large metal objects. With the ignition
OFF, press and hold the STEP button while turning
ON the ignition. Release the STEP button and the
CAL light will appear (about 10-15 seconds). Drive in
3 complete 360° (degree) circles. The CAL light will
turn off and the compass will be calibrated.
ZONE VARIANCE
Compass variance, also known as magnetic decli-
nation, is the difference in angle between magnetic
north and true geographic north. In some geographic
locations, the difference between magnetic and geo-
graphic north is great enough to cause the compass
to give false readings. For proper compass function,
the correct variance zone must be set. Refer to the
variance map for the correct variance zone in your
area. To check the variance zone, the ignition switch
must be ON and the compass/temperature displayed.
Press and hold the STEP button for about 5-15 sec-
onds until ZONE appears in the display, then release
the button. The number displayed is the variance
zone set in the compass. To change the zone refer to
the standard procedure later in this section.
OUTSIDE TEMPERATURE
Since the ambient temperature sensor is in close
proximity to the radiator, it can pick up engine heat
giving a false "high" outside air temperature reading
- known as "Heat Soak". In order to display a more
correct outside temperature, the overhead console
will not increase the displayed temperature until it
detects movement in the compass over a two-minute
period, to insure that there is adequate airflow over
the sensor. "Movement over a two minute period" is
best understood as once in the first minute, then
some more detected movement in the second minute.
If the display shows an open circuit OC ( or -49° F
(-45° C) then there is an OPEN CIRCUIT or a miss-
ing sensor and the condition must be corrected. Keep
in mind that after a repair is made, the vehicle may
need to be driven to update the temperature for the
reasons described above. Even if the engine is cool, it
will not increase from -49°F without detecting move-
ment.
STANDARD PROCEDURE
STANDARD PROCEDURE - COMPASS
CALIBRATION
CAUTION: Do not place any external magnets, such
as magnetic roof mount antennas, in the vicinity of
the compass. Do not use magnetic tools when ser-
vicing the overhead console.
The electronic compass features a self-calibrating
design, which simplifies the calibration procedure.
This feature automatically updates the compass cali-
bration while the vehicle is being driven. This allows
the compass unit to compensate for small changes in
the residual magnetism that the vehicle may acquire
during normal use. If the compass readings appear to
be erratic or out of calibration, perform the following
calibration procedure. Also, new service replacement
compass mini-trip computer modules must have their
compass calibrated using this procedure. Do not
attempt to calibrate the compass near large metal
objects such as other vehicles, large buildings, or
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