AC is currently not functioning and seeing the following diagnostic codes on my 1998 E300 TD, 58,000 Miles

B1231 - ECT Sensor (B11/4)
B1234 - Sun Sensor (B32)
B1459 - Series Interface (K2) Connection to instrument cluster(A1)

I have replaced Refrigerant Temperature Sensor, cleared diagnostic codes (and do not see any new ones)

AC Diagnostic actual values (original stop/running & after sensor replacement-stop/running) and Mercedes service are:

1-(37,37)(32,32)(29,29)
2-(37,40)(30,30)(33,33)
3-(40,40)(34,34)(26,23)
4-(40,40)(34,34)(26,22)
5-(54,55)(33,34)(28,14 up to 19)
6-(83,84)(37,up to 66)(82,81)
7-(00,00)(00,00)(07,17)
8-(52,55)(32,32)(40,54)
9-(05,05)(05,05)(05,01)
10-(4.5,4.5)(6.0,6.0)(3.5,3.5)
11-(4.3,4.3)(4.3,4.0)(3.9,3.9)
12-(4.2,4.2)(4.3,4.3)(4.2,4.2)
20-(0.0,0.0)(0.0,0.0)(0.0,6.0)
21-(00,06)(00,06)(00,06)
22-(00,00)(00,00)(00,00)
23-(00,00)(00,00(00,00)
24-(11.5,13.0)(11.2,11.3)(11.6,12.6)
40-(71,71)(71,71)(71,71)
41-(34,34)(34,34)(34,34)
42-(72,72)(72,72)(72,72)
43-(152,152)(168,168)(168,168)

Learned a couple of things doing searches:
Didn't know how to clear codes - just hit both auto buttons at the same time.

From other threads it appears that I need a:

Refrigerant Temperature Sensor part number: 210 830 05 72

I have replaced sensor but am concerned that diagnostic value # 7 = 00. Shouldn't this number be greater than that? I am not seeing any diagnostic error codes at this time. If Freon was low wouldn't I get a diagnostic error code?

I brought the car to the local Mercedes dealer this morning.

I asked Mercedes regarding a freon diagnostic error and they told me in 1998 there were no sensors for freon. Mercedes diagnostics:

"Verified that A/C was blowing warm air, recovered R134a from A/C system, only pulled 0.02ibs of R134a, this indicates a leak in system, pulled vacuum, recharged A/C system to 2.20lbs of R134a. Also installed A/C dye into system, when A/C blows warm air again customer to return for further diagnosis & repairs."

Quick conclusion:

MB has not leaked Freon and values are same as previously noted above. MB in Sarasota, FL & service department was excellent. The only place that I could find the refrigerant temperature sensor last week was at the Fort Meyers MB dealer. Just an FYI relating to customer service and my experience there. The customer service representative there was a pompous a&#%& and for that reason along I would never return to that dealership. The parts person on the other hand was polite and pleasant to deal with.

In conclusion it turned out to be the evaporator coil. The freon leaked out in a matter of a few weeks. This is sad as the car has only 58,000 miles on it to see this go. I had the same issue with an E320 with 79,000. Before these two owned two MB diesels (purchased new) that ran and ran and were sold well into the 150,000 mile range with no real problems. I guess that's why MB is not scoring too well anymore with Consumer Reports eh? I wonder how the Germans automakers feel now that the Japanese vehicles are on the average scoring higher than their vehicles. I guess maybe its time for a Lexus.