A/C Diagnostic Process
When a customer presents an A/C concern, do the following procedure to identify the cause of the problem.

1.
Confirm the type of concern.
If a customer complains about an A/C performance problem, go to step 2.
If a customer complains about an A/C noise problem, do the A/C system noise check.

2.
Do the A/C system inspection and repair any problems. If no problems are found, go to step 3.

3.
Recover the refrigerant from the A/C system and measure the refrigerant charge from the A/C system using an R134a A/C automatic recovery, recycle, recharge machine that meets SAE J2788 standards.
If the refrigerant charge is within specifications, go to step 5.
If the refrigerant charge is significantly under specifications, go to step 4.
If the refrigerant charge is significantly over specifications, go to step 5.

4.
Do the refrigerant leak check and repair any leaks. If no leaks are found, go to step 5.

5.
If vent temperature or suction/discharge pressures are within specifications, the repair is confirmed and the A/C diagnostic process is complete.
If vent temperature or suction/discharge pressures are not within specifications, a problem may still exist. Return to step 2, and recheck your test procedures.