AUTO 157 - Heating and Air Conditioning Level 2

1. Complete general A/C System diagnosis and Repair Level 2 NATEF tasks as listed below.
   1. Identify and interpret heating and air conditioning problems; determine necessary action.
   2. Research applicable vehicle and service information, vehicle service history, service precautions, and technical service bulletins.
   3. Performance test A/C system; identify problems.
   4. Identify abnormal operating noises in the A/C system; determine necessary action.
   5. Identify refrigerant type; select and connect proper gauge set; record temperature and pressure readings.
   6. Leak test A/C system; determine necessary action
   7. Inspect condition of refrigerant oil removed from A/C system; determine necessary action.
   8. Determine recommended oil and oil capacity for system application.
   9. Using a scan tool, observe and record related HVAC data and trouble codes.
2. Complete Level 2 NATEF tasks related to Refrigeration System Components as listed below.
   1. Inspect and replace A/C compressor drive belts, pulleys, and tensioners; determine necessary action.
   2. Inspect, test, service or replace A/C compressor clutch components and/or assembly; check compressor clutch air gap; adjust as needed.
   3. Remove, inspect, and reinstall A/C compressor and mountings; determine recommended oil quantity.
   4. Identify hybrid vehicle A/C system electrical circuits and the service/safety precautions.
   5. Determine need for an additional A/C system filter; perform necessary action.
   6. Remove and inspect A/C system mufflers, hoses, lines, fittings, O-rings, seals, and service valves; perform necessary action.
   7. Inspect A/C condenser for airflow restrictions; determine necessary action.
   8. Remove, inspect, and reinstall receiver/drier or accumulator/drier; determine recommended oil quantity.
   9. Remove, inspect, and install expansion valve or orifice (expansion) tube.
   10. Inspect evaporator housing water drain; perform necessary action.
3. Complete Level 2 NATEF tasks related to Heating, Ventilation, and Engine Cooling Systems Diagnosis and Repair as listed below.
   1. Inspect engine cooling and heater systems hoses; perform necessary action.
   2. Inspect and test heater control valve(s); perform necessary action.
4. Complete Level 2 NATEF tasks related to Operating Systems and Related Controls Diagnosis and Repair as listed below.
   1. Inspect and test A/C-heater blower motors, resistors, switches, relays, wiring, and protection devices; perform necessary action.
   2. Diagnose A/C compressor clutch control systems; determine necessary action.
   3. Diagnose malfunctions in the vacuum, mechanical, and electrical components and controls of the heating, ventilation, and A/C (HVAC) system; determine necessary action.
   4. Inspect and test A/C-heater control panel assembly; determine necessary action.
   5. Inspect and test A/C-heater control cables, motors, and linkages; perform necessary action.
   6. Inspect A/C-heater ducts, doors, hoses, cabin filters, and outlets; perform necessary action.
   7. Identify the source of A/C system odors.
   8. Check operation of automatic or semi-automatic heating, ventilation, and air-conditioning (HVAC) control systems; determine necessary action.
5. Complete Level 2 NATEF tasks related to Refrigerant Recovery, Recycling, and Handling as listed below.
   1. Perform correct use and maintenance of refrigerant handling equipment according to equipment manufacturer's standards.
   2. Identify and recover A/C system refrigerant.
   3. Recycle, label, and store refrigerant.
   4. Evacuate and charge A/C system; add refrigerant oil as required.