Message Systems Chrysler PT Cruiser I

Scheme 1

The overhead console includes the Compass/Temperature read-out and two reading and courtesy lamps. This display provides the outside temperature and one of eight compass readings to indicate the direction the vehicle is facing. The outside temperature is monitored by the ambient temperature sensor mounted on the support brace in front of the A/C condenser, behind the front grille. The ambient temperature is hardwired directly to the overhead console. On vehicles equipped with a power sunroof option, the overhead console also houses the power sunroof switch between the two reading and courtesy lamps. (Scheme 1) The overhead console is snapped into place near the front of the vehicle's roof and clips on the headliner, at the rear of the overhead console. There is a STEP button for the compass/temperature read-out located forward of the sunroof switch (if equipped), and between the map/reading/courtesy lamps.

The overhead console is equipped with two individual reading and courtesy lamps. The lamp lenses are the only visible components of these lamps. The reading and courtesy lamp lenses are mounted near the rear of the overhead console housing. Each lamp has its own switch, bulb and lens; but both lamps share a common lamp housing within the overhead console. Each lamp is designed and aimed to provide illumination that will be directed only to that side of the vehicle on which the lamp is located.

The reading and courtesy lamp lenses and the lamp housing unit are serviced only as a unit with the overhead console housing. If either of the lamp lenses or the lamp housing is faulty or damaged, the overhead console housing unit must be replaced.

OPERATION

There is a STEP button to display the compass/temperature, and can be read in either F° or C°. When the vehicle is first turned ON, you may select to have the overhead console

1. Blank display
2. Compass/Temperature displayed in Fahrenheit
3. Compass/Temperature displayed in Celsius

To put the compass/temperature in the F° display, press the STEP button once. To put the compass/temperature 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 overhead console are activated by the door jamb switches. When all of the doors are closed, these lamps can be individually activated by depressing the corresponding 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 second 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 eliminates 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) circles in an area free from large metal or metallic objects, the CAL symbol will turn off and the compass will function normally.

MANUAL COMPASS CALIBRATION

If the compass appears to be in the locked up position, 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 declination, is the difference in angle between magnetic north and true geographic north. In some geographic locations, the difference between magnetic and geographic north is great enough to cause the compass to give false readings. For proper compass function, the correct variance zone must be set. (Scheme 2)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 seconds 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.

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 missing 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 movement.

COMPASS CALIBRATION

The electronic compass features a self-calibrating design, which simplifies the calibration procedure. This feature automatically updates the compass calibration 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 bridges; or, near overhead or underground power lines.

1. Start the engine. If the compass/temperature data is not currently being displayed, momentarily depress and release the Step push button (this unlabeled button is located directly behind the overhead console display screen) to step through the display options until you have reached the compass/temperature display.
2. Depress the Step push button, until "ZONE" appears in the display (approx. 5-10 seconds), then "CAL" will be displayed. Release the Step button when CAL is displayed. The "CAL" in the display indicates that the compass is in the calibration mode.
3. Drive the vehicle on a level surface, at least fifty feet away from large metal objects and power lines, in all four compass directions, such as driving around a city block several times or driving in two to three complete circles at a slow speed (approx. 5 mph) until the CAL is no longer displayed.
4. Finally, set the proper zone/variance for the area you are in, when in manual override mode for calibration, it defaults to zone 8.

Note. If the "CAL" message remains in the display, either there is excessive magnetism near the compass, or the unit is faulty. Repeat the calibration procedure at least one more time.

Note. If the wrong direction is still indicated in the compass display, the area selected for calibration may be too close to a strong magnetic field. Repeat the calibration procedure in another location.

COMPASS VARIATION ADJUSTMENT

Compass variance, also known as magnetic declination, is the difference in angle between magnetic north and true geographic north. In some geographic locations, the difference between magnetic and geographic north is great enough to cause the compass to give false readings.

If a customer moves, or drives across zones the compass variation will have to be reprogrammed so that the compass will display the correct readings. If problems like these occur, the compass variance must be set. Use the following procedure to program the compass zone variation.

Scheme 2

1. Using the Variance Zone map, find your geographic location and note the zone number. (Scheme 2)
2. Turn the ignition switch to the On position. If the compass/temperature data is not currently being displayed, momentarily depress and release the Step push button to step through the display options until you have reached the compass/temperature display.
3. Depress the Step push button and hold down until the compass mini-trip computer enters the variation adjustment mode and "VAR" along with the current variance zone will appear in the display.
4. Momentarily depress and release the Step push button to step through the zone numbers, until the zone number for your geographic location appears in the display.
5. After five seconds, the displayed zone will automatically be set in the compass mini-trip computer module memory and normal operation will resume.
6. Confirm that the correct directions are now indicated by the compass.

COMPASS DEMAGNETIZING

A degaussing tool (Special Tool 6029) is used to demagnetize, or degauss, the overhead console forward mounting screw and the roof panel above the overhead console. Equivalent units must be rated as continuous duty for 110/115 volts and 60 Hz. They must also have a field strength of over 350 gauss at 7 millimeters (0.25 inch) beyond the tip of the probe.

To demagnetize the roof panel and the overhead console forward mounting screw, proceed as follows

Scheme 3

Scheme 4

1. Be certain that the ignition switch is in the Off position, before you begin the demagnetizing procedure.
2. Connect the degaussing tool to an electrical outlet, while keeping the tool at least 61 centimeters (2 feet) away from the compass unit. (Scheme 3)
3. Slowly approach the head of the overhead console forward mounting screw with the degaussing tool connected.
4. Contact the head of the screw with the plastic coated tip of the degaussing tool for about two seconds.
5. With the degaussing tool still energized, slowly back it away from the screw. When the tip of the tool is at least 61 centimeters (2 feet) from the screw head, disconnect the tool.
6. Place a piece of paper approximately 22 by 28 centimeters (8.5 by 11 inches), oriented on the vehicle lengthwise from front to rear, on the center line of the roof at the windshield header. (Scheme 4) The purpose of the paper is to protect the roof panel from scratches, and to define the area to be demagnetized.
7. Connect the degaussing tool to an electrical outlet, while keeping the tool at least 61 centimeters (2 feet) away from the compass unit.
8. Slowly approach the center line of the roof panel at the windshield header, with the degaussing tool connected.
9. Contact the roof panel with the plastic coated tip of the degaussing tool. Be sure that the template is in place to avoid scratching the roof panel. Using a slow, back-and-forth sweeping motion, and allowing 13 millimeters (0.50 inch) between passes, move the tool at least 11 centimeters (4 inches) to each side of the roof center line, and 28 centimeters (11 inches) back from the windshield header.
10. With the degaussing tool still energized, slowly back it away from the roof panel. When the tip of the tool is at least 61 centimeters (2 feet) from the roof panel, disconnect the tool.
11. Calibrate the compass and adjust the compass variance. Refer to «COMPASS VARIATION ADJUSTMENT»(/chrysler/pt-cruiser/i-2000-2010/remont/accessories-control-systems/#message-systems__compass-variation-adjustment) and «COMPASS CALIBRATION»(/chrysler/pt-cruiser/i-2000-2010/remont/accessories-control-systems/#message-systems__compass-calibration) for the procedures.

REMOVAL

1. Disconnect and isolate the negative battery cable.
2. Grasp the front of the overhead console and pull downward to disconnect the front retaining clips.
3. Slide the overhead console forward to disengage the rear tabs from the headliner.
4. Disconnect the overhead console wire connector.
5. Unsnap compass module from inner roof panel. Push module all the way forward to disengage the front retaining clip. Once the front clip is disconnected, push the module all the way rearward to disengage the rear retaining clip.
6. Remove console from vehicle.

INSTALLATION

1. Position overhead console into vehicle and snap compass module onto inner roof panel.
2. Connect overhead console wire harness connector.
3. Engage the rear tabs on the overhead console into the headliner.
4. Align the front retaining clips of the overhead console with the corresponding holes in the inner roof panel and firmly snap into place.
5. Connect the battery negative cable.
6. Calibrate compass «(Refer to ELECTRICAL/OVERHEAD CONSOLE - STANDARD PROCEDURE)»(/chrysler/pt-cruiser/i-2000-2010/remont/accessories-control-systems/#message-systems) .

Scheme 5

DESCRIPTION

Ambient air temperature is monitored by the compass/temperature display unit. It receives a hard wired input from the ambient temperature sensor. The ambient temperature sensor is a variable resistor mounted to a bracket that is secured with a nut to the bracket in front of the A/C condenser, behind the radiator grille.

The ambient temperature sensor cannot be adjusted or repaired and, if faulty or damaged, it must be replaced.

The ambient temperature sensor is a variable resistor that operates on a five-volt reference signal. The resistance in the sensor changes as temperature changes, changing the temperature sensor signal circuit voltage to compass/temperature display unit. Based upon the resistance in the sensor, the compass/temperature display unit senses a specific voltage on the temperature sensor signal circuit, which it is programmed to correspond to a specific temperature. The compass/temperature display unit then displays the proper ambient temperature.

AMBIENT TEMPERATURE SENSOR

The thermometer function is supported by the ambient temperature sensor, a wiring circuit, and the compass/temperature display unit.

If the display shows OC (-49°F (-45°C) or SC (140°F (60°C), there is an OPEN or SHORT CIRCUIT and it must be repaired before the VFD can be tested.

The ambient temperature sensor circuit can also be diagnosed using the following Sensor Test, and Sensor Circuit Test. If the temperature sensor and circuit are confirmed to be OK, but the temperature display is inoperative or incorrect, replace the compass/temperature display.

Scheme 6

1. Turn the ignition switch to the OFF position. Disconnect and isolate the battery negative cable. (Scheme 6) Disconnect the ambient temperature sensor wire harness connector.
2. Measure the resistance of the ambient temperature sensor. At room temperature (approx. 68°F), the sensor resistance should be between 9-11 Kilohms (9000-11000 ohms). The sensor resistance should read between these two values. If OK, refer to «SENSOR CIRCUIT TESTING»(/chrysler/pt-cruiser/i-2000-2010/remont/accessories-control-systems/#message-systems__sensor-circuit-testing). If not OK, replace the faulty ambient temperature sensor.

SENSOR CIRCUIT TESTING

1. Turn the ignition switch to the OFF position. Disconnect and isolate the battery negative cable. Disconnect the ambient temperature sensor wire harness connector and the compass/temperature display unit wire harness connector.
2. Connect a jumper wire between the two terminals in the body half of the ambient temperature sensor wire harness connector.
3. Check for continuity between the sensor return circuit and the ambient temperature sensor signal circuit cavities of the compass/temperature display unit wire harness connector. There should be continuity. If OK, go to step 4 . If not OK, repair the open sensor return circuit or ambient temperature sensor signal circuit to the ambient temperature sensor as required.
4. Remove the jumper wire from the body half of the ambient temperature sensor wire harness connector. Check for continuity between the sensor return circuit cavity of the compass/temperature display unit wire harness connector and a good ground. There should be no continuity. If OK, go to step 5 . If not OK, repair the shorted sensor return circuit as required.
5. Check for continuity between the ambient temperature sensor signal circuit cavity of the compass/temperature display unit wire harness connector and a good ground. There should be no continuity. If OK, replace the compass/temperature display unit. If not OK, repair the shorted ambient temperature sensor signal circuit as required.

Scheme 7

1. Open hood.
2. Working through the hole in the top center of the grille, remove the one retaining nut from the appropriate ambient temperature sensor. (Scheme 7) 1 - Air Temperature Sensor - NGC Engine Controller 2 - Air Temperature Sensor - Overhead Console 3 - Radiator Closure Panel
3. Disconnect the ambient air temperature sensor electrical connector and remove the sensor from the vehicle.

1. Install the one retaining nut to ambient temperature sensor.
2. Connect the battery negative cable.
3. Close hood.

See also:
• STANDARD PROCEDURE
• COMPASS VARIATION ADJUSTMENT
• COMPASS CALIBRATION
• SENSOR CIRCUIT TESTING