Circuit Test/Check - HVAC System

OPERATING CONDITIONS
The A/C clutch relay will be energized, when all of the following conditions are met:

- A/C requested.
- The sensor less than Wide Open Throttle (WOT).
- Engine speed less than 5000 RPM.
- ECT less than 124°C (255°F).
- Engine oil temperature less than 127°C (260°F).

To protect the A/C compressor, the A/C clutch relay will be de-energized, turned "OFF," if the vehicle speed is greater than 132 mph for 3 minutes.

DIAGNOSIS
Chart C-10 should be used for diagnosing the electrical portion of the A/C circuit. Refer to Computers and Control Systems / System Diagnosis. Testing and Inspection

The Tech 1 will be used in diagnosing the system, as it has the ability to monitor the A/C request input to the PCM, A/C status, A/C system pressure, as well as displaying when the ECM has commanded the A/C clutch "ON."