GM climate control diagnostics
From Knowledgebase
The V8, 100, 200, 5000 series Climate Control unit is a GM unit with diagnostic capabilities. These seem to be known to have diagnostic functions thru 1991 or so.
See: List of climate control codes
All V8's have ability to report voltage
- On the HVAC controller, press and hold "off" then "outside temp", then release both.
- Press "Warmer" until you get to channel 11
- Press "outside temp" again.
Voila, you now have voltage.
If you want to leave the heater on whilst going it, hold "outside temp" first, then go for the "off" button.
Robert A. Dupree
The CC 92+ climatic units have versatile diagnostic capabilities (61 channels). As for voltage, you have 3 options:
- Actual fresh air blower voltage (Ch18)
- Specified fresh air blower valtage (Ch19)
- A/C compressor (A/C clutch) voltage (Ch20) – with this you can actually check the on-board voltage.
Hope this helps to know your V8 better.
