MES 1.3 aircon pressure

[mr-mac]

Was wondering if you could help,

Got MES 1.3 plugged in to 2005 156 20v jtd mjet and I'm trying to read the aircon gas pressure.

Unfortunately it does not return any value at all. I guess it's not my car as my friend also tried to do same in his 2007 147 1.9 jtdm with his copy of FES and got same results.

Was wondering if you could clarify if we should be able to read this value or not as it's difficult to diagnose whether system needs a re-charge or if sensor is misreading without.

It may be it doesn't have a pressure sensor and just a switch for low/high but would be surprised as most do.

Thanks kindly

John

[s130]

You are using Adaptor Cable 1 ? This connects the K Line Pin-7, to Pin 9.

[mr-mac]

No, because pin 9 would be for connecting to climate control ECU... which has things like outside temp, inside temp, sunlight, fan & flap details etc.

The engine ECU has things like Aircon compressor, aircon pressure, fans etc...

Regardless if I didn't have correct adapter\pins shorted then I would fail to connect to the particular ECU rather than have a single data point provide no number at all. It just sits and says bar where as most other info points will say what measurement is then when ticked switch to showing figure.

[mr-mac]

Also I notice the odometer in engine ECU is returning 0 and I am 100% sure the 16/20v jtd's record odometer reading in ECU.

John

[s130]

Re connector, yes you are right I had forgotten there was an aircon pressure sensor on the engine ECU readings. Sorry to all for any confusion.

Regarding the ECU odometer value being zero then I have this exact same problem on my Croma which uses the smae ECU. This is a known "feature" and has been discussed before. In my case my ECU displayed a different value to the dashboard odometer. A long long time later the ECU then started to display zero.

[mr-mac]

Thanks kindly,

So ECU looses odometer??

Gonna read with the abandoned alfadiag later and see if I get the same results as I'm sure at some point on some software I did see a reading for pressure but maybe just being a retard lol.

Also got a door switch pack to give to local Alfa indie (cp in Dundee) so if he asks what I want for it i'll ask if he can read odometer and aircon pressure quickly using their garage obd stuff (should take him 30secs so sounds a fair deal). If they get no reading and 0.0km then we can be sure it's a car issue certainly useful feedback anyway.

John

[mr-mac]

Maybe there isn't a pressure sensor, maybe it's just the pressure switch (stops it running if under/over).

Is there an ecu parameter to show pressure switch condition? Or does anyone know if 156/147 later cars should read exact pressure in system? The sensor on a 156 has 5 pins so expect it should/could read pressure too

John