Air conditioning is switched on by push button located on right side of control panel. see scheme 1 A/C system will operate only at temperatures greater than 37°F (3°C) with engine on. At least one air outlet must be open when operating A/C system, to prevent evaporator freeze-up.
Blower control button allows volume of air entering passenger compartment to be varied. Airflow increases as "+" side of button is depressed, and decreases as "-" side of button is depressed. If "-" side of button is depressed at minimum blower speed, all data disappears from display. Blower, heater, and A/C are deactivated, and flow of outside air is switched off.
Pushing recirculated air button cuts off outside airflow.
Temperature control buttons determine temperature of air entering driver-side or passenger-side compartments. Pressing left side of button will decrease air temperature. Pressing right side of button will increase air temperature. Driver and front passenger can select individual temperature ranges.
Accessing Input Signals
- Automatic A/C-heater control panel can display 12 input signals. To access signals, simultaneously press AUTO and rear defogger buttons. Press fan rocker button to toggle through displays. See «A/C-HEATER CONTROL UNIT INPUT SIGNALS»(ref-149611-S29793366282002101600000) table.
- To exit A/C-heater control panel display, simultaneously press recirculated air and AUTO buttons, or turn ignition off. For identifying A/C-heater control panel connector terminals and related inputs, grounds and outputs, see «A/C-HEATER CONTROL UNIT CONNECTOR TERMINAL IDENTIFICATION»(ref-149611-S24424174942002101600000) table. (Scheme 18)and (Scheme 19).
| Test No. | Signal |
|---|---|
| 1 | Interior Temperature Sensor (1) |
| 2 | Exterior Temperature Sensor (1) |
| 3 | Left Heater Core Temperature Sensor (1) |
| 4 | Right Heater Core Temperature Sensor (1) |
| 5 | Evaporator Temperature Sensor (1) |
| 6 | Engine RPM Input |
| 7 | Vehicle Speed Input |
| 8 | "Y" Factor Value |
| 9 | Fresh Air Flap Position In Percent (2) |
| 10 | AUC Sensor Voltage (If Equipped) |
| 11 | Battery Voltage |
| 12 | Software Version |
| (1) Temperatures are displayed in degrees Celsius. (2) Decimal point is not displayed (995 equals 99.5). | |
| (1) | Temperatures are displayed in degrees Celsius. |
| (2) | Decimal point is not displayed (995 equals 99.5). |
A/C-HEATER CONTROL UNIT INPUT SIGNALS
| Connector Terminal No. | Signal Type | Description |
|---|---|---|
| 1 | Input | Exterior Temperature Sensor |
| 2 | Input | Evaporator Temperature Sensor |
| 3 | Input | Left Heater Core Temperature Sensor |
| 4 | Input | Right Heater Core Temperature Sensor |
| 5 | Input | VSS Signal To Instrument Cluster |
| 6 | Input | Engine RPM |
| 7 | Input | |
| 8 | Output | "Y" Factor Value |
| 9 | Input | Starter |
| 10 | Output | RPM Signal Increase |
| 11 | Output | A/C Pressure Switch |
| 12 | Output | Rear Window |
| 13 | Output | Right Water Valve Activation |
| 14 | Output | Fresh Air Flap Motor Activation |
| 15 | Output | Fresh Air Flap Motor Activation |
| 16 | Output | Fresh Air Flap Motor Activation |
| 17 | Output | Fresh Air Flap Motor Activation |
| 18 | Output | Left Water Valve Activation |
| 19 | Output | Auxiliary A/C Condenser Fan Activation |
| 20 | Input | Independent Ventilation |
| 21 | Ground | Control Panel |
| 22 | Ground | Air Mixing Actuator |
| 23 | Ground | Control Panel |
| 24 | Input | Voltage (Switched) |
| 25 | Input | Voltage (Hot Always) |
| 26 | Input/Output | Data Link Connector |
| (1) See WIRING DIAGRAMS for corresponding wire colors. | ||
| (1) | See WIRING DIAGRAMS for corresponding wire colors. |
A/C-HEATER CONTROL UNIT CONNECTOR TERMINAL IDENTIFICATION (1)
Scheme 18
Scheme 19
EVAPORATOR & EXPANSION VALVE
Note. It may be necessary to remove glove box assembly from vehicle to access evaporator core. see scheme 6