C36 AMG, C43 AMG (W202) 1995 - 2000

A/C Issue (Blows Cold then Ambient after Reaches Op Temp)

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Old Feb 24, 2019 | 12:57 PM
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From: South Florida
1998 C43, 2017 Honda Accord Sport
A/C Issue (Blows Cold then Ambient after Reaches Op Temp)

Hi All,

I've been dealing with this mystery for over a year now, but it has me baffled. Have yet to take it to a shop to diagnose, but am reaching that point.

The issue
Blows wonderfully cold but once the car warms up to operating temp (very quickly in FL; like 5 minutes). The air temp becomes ambient (NOT hot).

I've replaced all of the following within the last 5k miles
  • Compressor (this was needed as it was leaking)
    • Freon recharge (naturally, after replacing the compressor)
  • Water pump
  • Receiver drier
  • Duo heater control valve

HVAC Live Data (outside temp was 80*F at time of test)
01 77*F
02 90*F
03 78*F
05 15 8
06 14 1
07 09 9 (I figured this was a tad low so, pulled it again a few minutes later and got 14 8)
08 11 1
09 37*F (not sure what this value is for)
10 215
20 00 (pulled again few minutes later: 030)
21 06 0
22 00 0
23 00 0
24 14.0
40 03
41 03
42 02
(the codes below I have no idea what they are as my code sheet was for w208/w209)
43 6-C
50 78*F
51 74*F
52 46*F (this may be the culprit but I don't know what it is)
54 OFF

Stored Error Codes

I checked these and cleared them before pulling live data.
227 Outside temp sensor (this broke when I was in my accident - replaced)
416 Coolant circulation pump (broke when my accessory belt snapped - replaced)
417 Left duovalve (replaced as troubleshooting measure)
419 A/C clutch (compressor was leaking; replaced)

After gathering live data and letting car run at idle for 10 minutes
No codes

Any thoughts, gents?
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Old Feb 27, 2019 | 08:17 PM
  #2  
importfan21's Avatar
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From: South Florida
1998 C43, 2017 Honda Accord Sport
Originally Posted by Plutoe
Your compressor is faulty!!----see 7 and 8,7 should be 15 and on planet earth 8 then has to be 135 while 5 should be 41
For 07, note that I retook the measurement and got 14 8 as that is live data and the pressure fluctuates constantly. Not worried about 07 reading unless it's consistently low.
For 08, 111 seems to be within range as well (111 was taken the same time as the first 07 measurement)

05, is the temperature at the evap sensor, correct? (I'm using Marcus' guide for the w208 so I hope the codes are the same for w202). Is a 30 degree difference that significant for that sensor? I'm a HVAC dummy.
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