A/c-Heater System - Automatic: Other Dodge Intrepid I

Automatic Mode

In this mode, the system controls temperature, fan speed, and operating mode automatically. Light Emitting Diodes (LEDs) in push buttons indicate which mode is active.

Semiautomatic Mode

If blower/fan speed is selected manually, the system will control temperature and mode automatically.

Manual Mode

If both blower/fan speed and mode are selected manually, or if full heat or full cooling is selected, both blower/fan speed and temperature will be controlled to knob position selected.

A/C Button

Pressing A/C button turns A/C system on or off. (Scheme 4) When A/C button is pressed, a signal is sent to indicate button status to Body Control Module (BCM).

Blower Control Knob

In semiautomatic mode, blower/fan speed is controlled by rotating blower control knob.

Vacuum Fluorescent Display (VFD)

The VFD displays operating mode and selected temperature.

Temperature Control Knob

Temperature control knob allows user to select interior temperature. Clockwise rotation increases temperature setting. Counterclockwise rotation decreases temperature.

Mode Controls

There are 10 buttons which select air delivery mode: automatic, off, floor, mix, A/C, front defrost, panel (vent), bi-level, recirculated air, and rear defogger.

Scheme 4

BLOWER MOTOR POWER MODULE

Blower motor power module controls blower motor speed, through a signal received from BCM.

EVAPORATOR TEMPERATURE SENSOR

Evaporator temperature sensor provides one of the inputs required to control A/C compressor clutch. Sensor monitors evaporator temperature, and sends signal to the BCM to turn off the compressor before evaporator freeze-up occurs.

SUNLOAD SENSOR

Sunload sensor is located on top of the instrument panel. Sunload sensor senses level of sunlight entering vehicle to determine whether additional cooling is needed.

IN-VEHICLE TEMPERATURE SENSOR

In-vehicle temperature sensor is located behind right side of instrument panel. It sends a signal to the body controller, which is used to make temperature adjustments. If sensor is open or shorted, digital display will turn off and system will revert to manual operation.

AMBIENT TEMPERATURE SENSOR

Ambient temperature sensor is located inside left front bumper beam. This thermistor monitors outside air temperature. BCM uses information provided by ambient sensor to regulate blower speed, temperature offsets, evaporator temperature, and mode control. If sensor fails, battery temperature input signal is used as back-up.

AUTOMATIC TEMPERATURE CONTROL RECALIBRATION

The Automatic Temperature Control (ATC) system must be recalibrated if the battery is disconnected or loses power. If it is not, the system will not operate properly. To recalibrate the system

1. When the battery power is restored, disconnect the electrical connector near the battery. Leave disconnected for at least 15 minutes. (Scheme 5)
2. Reconnect the connector. Start and run the engine for at least one minute. The ATC system is now calibrated

Scheme 5

CLIMATE TESTS Mode

This function allows user to perform partial charge and A/C-ON tests.

CLIMATE FAULTS Mode

This function allows user to perform engine and body computer fault tests and Automatic Temperature Control (ATC) head/panel tests.

CLIMATE STATE Mode

This function allows user to read states or values of a variety of sensors, inputs/outputs, monitors, and custom displays. This function also permits identification of Powertrain Control Module (PCM), Body Control Module (BCM), and ATC software versions.

CLIMATE ACTUATORS Mode

This function allows user to change engine RPM and exercise A/C-heater system relays and actuators, as well as in-vehicle temperature aspirator.

VEHICLE EQUIPMENT & SYSTEM PROBLEM ID

1. Connect DRB to data link (diagnostic) connector. see scheme 3 Turn ignition on. With DRB, select body system. If DRB does not display BUS OPERATIONAL message, check body control computer for bus failure messages. See appropriate article in ENGINE PERFORMANCE section. If BUS OPERATIONAL message is displayed, go to next step.
2. Select body controller. Select ATC system. If DRB displays NO RESPONSE, go to TEST 18A: IGNITION SWITCH OUTPUT CIRCUIT. If NO RESPONSE is not displayed, go to TEST 17A: AUTOMATIC TEMPERATURE CONTROL.

Note. See TEST 17A and TEST 18A in TROUBLE SHOOTING section.

Vehicle Preparation

1. Set parking brake. Set shift lever to Park position. Start and idle engine at 700 RPM. Set A/C controls to outside air, panel (vent) mode, full cool, and A/C button on. Set blower to high speed. Open windows. Set recirculated air button to off position.
2. Operate system for a few minutes to allow system to stabilize. Place a piece of cardboard over front part of condenser to maintain A/C pressure at 260 psi (18.3 kg/cm 2 ). This will stop cooling fans from alternating speeds and maintain a constant pressure.

Using DRB

Attach Thermocouple (80PK-1A) to liquid line as close to condenser outlet as possible. Connect DRB to data link connector. see scheme 3 Set DRB to LH CLIMATE CONTROL, SYSTEM TEST, and PARTIAL CHARGE TEST. The correct liquid line temperature range is calculated by DRB.

Using Manifold Gauge Set

1. Attach clamp-on thermocouple to liquid line as close to condenser outlet as possible. Connect gauge set to high side and low side connectors.
2. Note discharge pressure and liquid line temperature. Use REFRIGERANT CHARGE LEVEL table to determine if system is undercharged or overcharged.

Charge Level Corrections

Depending on system charge, make corrections 2 ounces at a time. After each correction, recheck readings to verify proper charge. Total system capacity is 28 ounces.

REFRIGERANT CHARGE LEVEL

1. Turn ignition on. Press OFF button on A/C-heater control panel. Place a piece of paper in sensor opening. If paper sticks to sensor opening, in-vehicle temperature sensor aspirator is working properly. Inspect for presence and condition of 2 foam seals. One seal is located behind name plate. The other is located near right center duct opening. Replace or repair seals as necessary.
2. Go to TEST 25B: IN-CAR TEMPERATURE SENSOR to test sensor in TROUBLE SHOOTING section.

Ensure sensor is not covered by papers, windshield wipers, top cover, or stickers on windshield installed in front of sensor. Go to TEST 25G: ATC SUNLOAD SENSOR CIRCUIT to test sensor in TROUBLE SHOOTING section.

* PLEASE READ FIRST *

COMPRESSOR