Published: 11-Jul-2014
Climate Control System - General Information - Climate Control System
Diagnosis and Testing
Principles of Operation
For a detailed description of the Climate Control System, refer to the relevant Description and Operation sections in the
Workshop Manual. REFER to:
Air Distribution and Filtering (412-01 Climate Control, Description and Operation), Air Distribution and Filtering (412-01 Climate Control, Description and Operation), Air Distribution and Filtering (412-01 Climate Control, Description and Operation), Heating and Ventilation (412-01 Climate Control, Description and Operation), Heating and Ventilation (412-01 Climate Control, Description and Operation), Heating and Ventilation (412-01 Climate Control, Description and Operation), Air Conditioning (412-01 Climate Control, Description and Operation), Air Conditioning (412-01 Climate Control, Description and Operation), Air Conditioning (412-01 Climate Control, Description and Operation), Control Components (412-01 Climate Control, Description and Operation), Control Components (412-01 Climate Control, Description and Operation), Control Components (412-01 Climate Control, Description and Operation), Electric Booster Heater (412-02 Auxiliary Climate Control, Description and Operation), Electric Booster Heater (412-02 Auxiliary Climate Control, Description and Operation), Electric Booster Heater (412-02 Auxiliary Climate Control, Description and Operation).
Inspection and Verification
WARNING: Servicing must be carried out by personnel familiar with both vehicle system and the charging and testing
equipment. All operations must be carried out in a well ventilated area away from open flame and heat sources.
CAUTION: Diagnosis by substitution from a donor vehicle is NOT acceptable. Substitution of control modules does not
guarantee confirmation of a fault, and may also cause additional faults in the vehicle being tested and/or the donor vehicle.
NOTE: Check and rectify basic faults before beginning diagnostic routines involving pinpoint tests.
1. Verify the customer concern
2. Visually inspect for obvious signs of damage and system integrity
Visual Inspection
Mechanical Electrical
Coolant level
Hose(s)
Coolant pump
Control flap(s)
Duct(s)
Vent(s)
Cabin air filter
Drive belt
Air conditioning compressor
Thermostatic expansion valve
Evaporator
Receiver drier
Air conditioning condenser
Refrigerant pipes Auxiliary
drive belt
Fuel fired booster heater
Fuel fired booster heater fuel pump
Fuel fired booster heater fuel pipes
Fuse(s)
Wiring harness
Electrical connectors
Blower
Air conditioning compressor
Electric cooling fan
Automatic Temperature Control Module (ATCM)
Refrigerant pressure sensor
3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to
the next step
4. If the cause is not visually evident, verify the symptom and refer to the Symptom Chart, alternatively check for
Diagnostic Trouble Codes (DTCs) and refer to the DTC Index
5. Check DDW for open campaigns. Refer to the corresponding bulletins and SSMs which may be valid for the specific
customer complaint and carry out the recommendations as required
