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Cadillac 04 DTS
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27 Posts
Discussion Starter #1
Very warn day here in NJ and I have no AC just blows hot air going to pull the codes but I can hear the compressor coming on what could be the problem if somebody could direct me to a thread that has some solutions I would be in debt to somebody.

Thank You.
 

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2005 Cadillac DeVille DTS
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150 Posts
You may never get codes - even if the system is nearly empty. You need to hook up a set of gauges.

Seems late '03 and later models don't set low refrigerant codes and kick out the compressor - even if the system is completely empty. The compressor will eventually disengage, but too low to prevent compressor damage in my opinion.

Maybe this is GM's way of keeping post warranty RO's up. Either that or engineer's felt most of the oil returns to the compressor on a low charge, so no harm if the compressor keeps running with next to no charge.

Joe
 

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White Diamond '03 DHS (with DTS floor shift)
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87,113 Posts
You may never get codes - even if the system is nearly empty. You need to hook up a set of gauges.

Seems late '03 and later models don't set low refrigerant codes and kick out the compressor - even if the system is completely empty. The compressor will eventually disengage, but too low to prevent compressor damage in my opinion.

Maybe this is GM's way of keeping post warranty RO's up. Either that or engineer's felt most of the oil returns to the compressor on a low charge, so no harm if the compressor keeps running with next to no charge.

Joe
Really? What brings you to this conclusion?
 

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Cadillac 04 DTS
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27 Posts
Discussion Starter #5
I added a can but no dice passenger side and rear are fine but the driver's side is cooking me I pulled the codes I got 408 and 429 so i guess i have a air mix door problem or whatever it is weather will be cool for a couple of days in jersey so i'll mess with it next weekend.
 

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2005 Cadillac DeVille DTS
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150 Posts
2 DeVilles. 1 SLS, and my own personal DeVille DTS. All of late '03 production and newer, and they all had either low charges or completely empty systems and no codes. It's been a total shock to me. On one DeVille where the compressor was still turning we recovered only 8 oz. All of them didn't require code clearing to re-engage the compressor... just dialed in the charge, and when the machine stopped, we started the engine and the compressor engaged.

I was thinking the problem on all these were perhaps bad pressure transducers, but since they were headed to the auction, we weren't going to fool with them. On my own DTS, I did replace the high pressure line, which had a new transducer, and even with an empty system (and under vacuum too) no SERVICE A/C SYSTEM message on DIC and no codes. The only time I was able to get the message and a code was by disconnecting the transducer. If I remember right, after reconnecting the connector the compressor came on without clearing the code (it just went to history).

Granted this is nothing scientific - could be other issues, bad module, or who knows - but 4 cars including my own makes me wonder that there must have been some kind of change. But I could be entirely off. Maybe if EWill3rd sees this he can shed some light, because I sure as heck would like to know!

Joe
 

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Cadillac 04 DTS
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27 Posts
Discussion Starter #7
I added a can but no dice passenger side and rear are fine but the driver's side is cooking me I pulled the codes I got 408 and 429 so i guess i have a air mix door problem or whatever it is weather will be cool for a couple of days in jersey so i'll mess with it next weekend.
If these codes coming up is there any way I can rig/fix this door and where is it located?
 

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White Diamond '03 DHS (with DTS floor shift)
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87,113 Posts
B0408 - Temperature Control #1 (Main/Front) Circuit Malfunction

B0429 - Temperature Control #3 Rear Circuit Range/Performance

Both actuators are under the dash. I'd strongly recommend a FSM.
 

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Cadillac 04 DTS
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27 Posts
Discussion Starter #10
B0408 - Temperature Control #1 (Main/Front) Circuit Malfunction

B0429 - Temperature Control #3 Rear Circuit Range/Performance

Both actuators are under the dash. I'd strongly recommend a FSM.
Where do I find a FSM for my car?
 

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1990 350 Brougham (The cruiser), 1988 Mark VII LSC (The DD)
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5,545 Posts
I got mine off Ebay for $20 for the Fleetwood and $30 for the Brougham.
 
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