General Description

General Description

The Air Conditioning electronic Control Module (A/CCM) located on the right-hand side of the Air Conditioning (A/C) unit, controls the functions of the system.

These functions include:
- In-car temperature control
- In-car humidity control (Air conditioning vehicles only)
- Air flow/volume and distribution

The temperature of the passenger compartment is continuously compared with the temperature selected on the control panel LCD. A digital microprocessor within the A/CCM receives the data signals. Comparison of these signals and those from system temperature sensors and feedback devices results in the appropriate output voltage changes needed to vary the blend of air flow into the passenger compartment.

Schematic View A/CCM Inputs & Outputs:

The climate control system peripherals communicate with the A/CCM via three main device categories comprising of manual inputs, automatic outputs and inputs, as shown.

Component Location Diagram:

1. Instrument pack
2. Fascia switch pack
3. Defrost servo.
4. Air distribution box
5. Solar sensor
6. Control panel
7. -
8. LH blower motor
9. Water valve
10. Circulation pump
11. Coolant temperature sensor
12. LH front fuse-box
13. Circulation pump relay
14. Ambient temperature sensor
15. A/C compressor
16. Compressor clutch relay
17. Trinary pressure switch
18. Radiator fan pressure switch
19. Control module
20. RH blower motor
21. -
22. Engine control module
23. Motorized in-car aspirator
24. -
25. A/C isolate relay
26. RH blower motor high speed relay
27. RH blower motor relay
28. LH blower motor high speed relay
29. LH blower motor relay


System Differences


NOTE: This data applies generally to both air conditioning and heater systems. System specific descriptions, procedures, tests etc. are indicated.


Heater only vehicles do not have the following installed:
- Solar sensor
- Clutch request and acknowledge circuitry.
- Refrigerant pressure switch.
- Control panel - deletion of air conditioning button.

6 cyl. engined vehicles do not have either the electrical load inhibit or the compressor lock sensor.

Heated Front Screen (HFS) is optional on both air conditioning and heater panel versions.