Packrat0113

06 civic lx AC issue. Start car and turn on Ac. Fans turn on,compressor kicks in and blows ice cold for about 20 seconds and then everything shuts down. Have put in new relay,pressure switch,evac and recharge.Just had on scanner and would not let ac communicate with scanner.Did system restore and still nothing. HELP!!!

ezone

A scanner can't do much with the HVAC system, but the HVAC system can do some limited self diagnosis. I think it's been posted here in the past, try searching.

The best a scanner can do would be in the PCM data list, if the scanner is good enough it can show the AC high side pressure, the AC request status, and the status of the compressor clutch relay and the status of the radiator fans.


Got pressure gauges?
What is the

Ambient temperature
and
Low and High pressure gauge readings when the system quits?
I assume you mean the compressor clutch turns off.....Do the radiator fans turn off too?

Or did you mean the blower fan in the dash shuts off?


What do you have to do to get the AC system to turn on again?

Packrat0113

Guy who checked the pressures said they were okay with the compressor not running. Compressor will only run for 20 seconds or so. The compressor clutch condenser fan and radiator fan all turn off and on together. Interior AC control keeps blowing warm air. Shut the engine down completely and restart the car at everything runs for 20 seconds and turns off again every time. Has a lot of people stumped. Hope you can help

ezone

Ok, I would like to know what the pressures do while the engine is running.
More specifically-- what the pressures are doing leading up to the time the system shuts itself off. (If high side pressure climbs up near 500 PSI that's a big problem)

Next I would want to plug in my scanner so I can view live operating data to see if the AC request is still present. If it's still present then I'm probably looking for anything in the scanned data that would cause the PCM to turn the AC off as a safety measure. (AC HS pressure reading too high --and does that reading agree with a real pressure gauge--, ECT too high, things like that)

If the request status says "NO", then I'm probably going to be checking through the system from the HVAC dash panel to the evaporator thermostat to the MICU to the PCM to figure out why the AC REQUEST is not present.

Packrat0113

The pressures I think we're steady around 150 psi but I can't be sure 100%. The scanner could not communicate with the HVAC side while the Diagnostics were being run. Restore Des system and didn't help. Will get back to you when I can get gauges on it and get the information you requested and try the scanner again. Thanks

ezone

Pressures while the system is running will be very different than when it is not running.

As already stated, you will not read anything from the HVAC control unit in this car. The only AC operating data that can be found will be read through the PCM, and that's only if you have a scanner that can display it. (not all scanners can display all available data)

The HVAC panel is capable of some self diagnosis though it is not done with a scanner.
IIRC the info in this link was pretty close if not exactly the same
http://civic.hondafitjazz.com/A00/HT...000BBAT00.html

Packrat0113

Thanks I'll give it a shot and let you know what happens.