Operational Test

DIAGNOSIS
To diagnose the Electronic Climate Control (ECC) System in the shortest time and with the least amount of effort, it is important to know how a properly functioning system will perform. For diagnosis of all ECC functions, refer to CLIMATE CONTROL DIAGNOSIS.

A/C OPERATIONAL TEST

Check For A/C Related BCM Codes First

Before replacing A/C components, check for A/C related BCM codes and refer to 'BCM TROUBLE CODE DIAGNOSIS'. For more diagrams and diagnostic procedures on vacuum and electrical systems.

1. To get an indication that the electrical circuits are functioning properly, check that the compressor clutch engages, the cooling fans are operating properly, and that the blower operates at all five speeds. Select any mode except 'OFF.' (The blower motor will not operate in the 'OFF' mode.)
2. Touch the evaporator inlet pipe and the evaporator-to-accumulator pipe while the system is operating. If they feel about the same temperature a proper system charge level is indicated.
3. Air discharged from the proper outlets when the mode buttons are depressed is an indication of proper vacuum and actuator operation.