How to cancel error codes in a/c
 

I have issues with my '99 E320's a/c and after reading Steve Brotherton's very good article I retrieved the error codes:

B1231-ECT sensor
B1234-Sun sensor
B1459-Series interface connection to instrument cluster

I have just had the transmission changed and a major service done and the a/c stopped after that. May just be fluke but i'm not sure. I have heard that I may be able to just reset the error codes and all may be well and was wondering how to do this?
I have made a search on this board but can only find reset info for the older style of control panel.
Thanks for any help.

While in the DTC (Diagnositc Trouble Code) read out mode, cycle through all errors, then simultaniously press both Auto buttons > 2 seconds. The display should change. Pressing auto again will cancel the erase. Turn off ignition to end test. They should be gone. Let us know if this works, I got this from WIS.

:)
Yep it worked as you said and codes are now cleared.
Unfortunatly the a/c still blows hot so I am looking at the diagnostic values and will try and work out from them what is most likely the problem.
My local dealer wants to put leak detector in the system but I don't have any codes telling me this is a problem so am not sure if this is a waste of time and money.
Any other ideas out there?

I believe the DTC errors can stay in the system until someone actually clears them. So the errors you cleared out may not reflect its current state. Check the errors periodically to see if any comes back.

In the data read out where you step through things like temperatures and pressures, what does #7 read? The is the refrigerant pressure and I think it needs to be at least 3 for the compressor to turn (read from other posts). Mine goes to mid teens on hot days, above 80 F. When the car becomes cooler, it will drop back down to 5-6.

Check other threads, there is a lot of information out there but trying to find it can be difficult.

#7 reads ok at 05 cold and 14 running.
I noticed that #5 reads 100 cold and 107 running which I believe from other posts is the evaporator temperarure sensor and have heard that this is way too high and could be showing that the sensor is bad.
At least I have some more information now for when I go into the shop and should be able to persuade them not to just flush the system and run some leak check as the pressure seems fine to me so can't see how it is leaking.
The compressor sounds like it is cycling as it should which I believe shouldn't happen if I am low on refigerant. I also get the same sounds through the vents as I used to when the a/c was working so hopefully it's just a sensor.

I believe you could probably change the that sensor yourself. Do some searches, it will save you money.