Troubleshooting chart for vehicle air conditioning systems

Troubleshooting chart
for vehicle air conditioning systems

Introduction

The professional tips chart provides help and support when troubleshooting the air conditioning systems. This clearly arranged diagnosis guide will help you find the typical functional errors that may occur in air conditioning systems for vehicles

How to use the chart

Professional tips can only be performed properly if the appropriate workshop equipment is available. The required equipment can be found in our workshop catalogue. Follow the operations listed on the following pages step by step. Only then can you be certain to achieve a good result from your troubleshooting efforts.

• Step 1: Test conditions/preparations
• Step 2: Performance test air conditioning system
• Step 3: If a malfunction occurs, it must be grouped into one of the three specific types of errors, which are summarised in three standard worksheets.
  • Base table A: The air conditioning system does not cool
  • Base table B: The air conditioning system produces an inappropriate noise
  • Base table C: The air conditioning system produces an odour
• Step 4: The fault can then be diagnosed using the relevant worksheets. The specific worksheets provide useful assistance for troubleshooting.
  • Worksheet 1: Insufficient heat dissipation via the condenser
  • Worksheet 2: The refrigerant quantity is incorrect and non-condensible gases or moisture occur in the system
  • Worksheet 3: Faulty expansion valve
  • Worksheet 4: Fault in the suction pressure regulator (V5)
  • Worksheet 5: Fault in the compressor’s electrical magnetic coupling, i.e. the coupling slips or does not engage
  • Worksheet 6: The suction and pressure lines on the compressor are reversed
  • Worksheet 7: Stoppage in the refrigerant circuit
  • Worksheet 8: Ice formation in the evaporator
  • Worksheet 9: Faulty compressor
  • Worksheet 10: Penetration of hot air into the compartment/circulation of hot water in the heating system’s heat exchanger
  • Table