DIC results

[Keats]

6/26/23

I did not find anything to explain this situation on the forum.

 

I'm having problem with the A/C on my 2004 C5.

I've had the system checked and refilled twice and there is a tiny leak at the line leading into the evaporator core on the firewall side. I'm going to try a leak fix to see if it will seal the leak up.

Anyway, It was still blowing cool (Not Cold- about 60 degrees) air from the passenger side dash vents, but only warm air from the center vent and the drivers side dash vent near the door.

 

I checked the on board DIC today and got the following codes:

10PCM No Code

28 TCS No Code

40 BCM No Code

58 SDM No Code

60 IPC No Code

80 Radio ( nothing after that. I do have an after market radio installed)

99 HVAC 2 codes

A0 LDCM 3 codes

A1 RDCM 3 codes

A6 SCM No Codes

B0 RFA 1 code

So I went to manual and found the following:

99 HVAC Code B0361 H

99 HVAC Code B0367 H

A1 RDCM Code B2283 H

A1 RDCM Code B2285 H

A0 LDCM Code B2282 H

A0 LDCM Code B2284 H

B0 RFA    Code U1255H

 

I learned that the codes can have either a "C" or an "H" after them to designate a Current or a History situation.

All of mine reflect a History.

 

I swapped out the old dead battery about 2 months ago and I'm wondering if having a dead battery could cause a reading like I'm seeing in History.

U1255H is for Serial Data Line Malfunction. Perhaps when there was no power to the computer, it recorded that as a Data Line Malfunction? Could that apply to the other codes as well.

 

I do not want to simply erase the codes until I know how they were caused.

 

As for the warm air at the center and drivers side vents, I've read that this may be due to low refrigerant in the Evaporator and it's just not cold enough to blow cold air out of those vents. Hmmm?

 

I really do not want to pull the dash to get to the blend door actuators if I can help it. The "Mode" will switch from the dash to the defroster to the floor and to the dash/floor so apparently the vacuum that functions those Modes is working like it should.

 

Any tips or clues? It's getting really HOT out here and I sure would like to get my A/C up and running again.

 

Thanks,

Keats

Peoria

[TheCMSH]

Charge level is critical but sounds like you have a grasp on that.  What you probably have going on is a blend door issue.  Over time, they get out of sync, I don't know why but they do. Sometimes they even jam up or the gear teeth break off

 

There is a procedure to re-index the blend doors which is basically to pull the fuses for a bit, then re-install the fuses.  The blend doors will then cycle to their full open/full close limits.  The couple times I had airflow problems on mine, this fixed the issue.  I want to say its fuses 18 and 27 in the passenger footwell fuse block but I believe there is also one for the AC in the engine compartment fuse block  Consult your owners manual for those fuse numbers but I think thats accurate

 

This procedure used to be posted on the Corvette Forum as well if you want to hunt for it

[Keats]

Yea, I saw a You Tube on that for a Chevy Silverado. I have not checked that out yet. Wanted to fix the leak first. Thank you for the reply.

Keats

 

[Desertdawg]

You could be fighting both low Freon and the blend door issue…

I searched and found an old thread were I recalibrated the blend doors and it would blow cold on the drivers side for a few cycles. It’s worth a try.

https://www.arizonacorvetteenthusiasts.net/search/?&q=Blend&page=7&quick=1&search_and_or=or&sortby=relevancy

 

Look near the bottom for the procedure once you pull up the codes.

[Keats]

Tuesday

Desertdawg,

Could be. However when my tech recharged the system last time. It blew cold air out of the center vent. In fact it blew cold out of all vents. I'm still hanging onto the thought that it may be a low freon situation.

Fingers crossed.

Keats

Peoria