Jump to content
CaddyInfo Cadillac Forum

'99 Deville-Need heater help

Recommended Posts

Ok All, my '99 Deville isnt blowing heat on drivers side, pass side is like the desert. First off, only code is IPC U1255 Class 2 Comms Fail (which was there when I had heat). I have replaced the drivers actuator 3 times, replaced the A/C Module and flushed the hell out of the heater core ( Frontwards, Backwards, with chems, without, with shop air and without...) Pass side blows HOT and drivers side cool. This is same for A/C on AND off. What else could it be, the temp sensor in the duct??? To let actuator and module relearn, I disconnected the batt for 30 mins, then onced hooked up, let ignition left on for 3 mins, also, turned up, then down all of the way a bunch of times. HELP!!!

Link to comment
Share on other sites

The first thing you should do when diagnosing most problems is run the OBD codes, which you can do from the front seat in your Cadillac using the A/C buttons and the DIC; see the link in my signature block below. Please run the codes and post them here.

But it does sound like a vacuum line is off, or that there is a stuck temperature servo. The OBD codes will tell the tale.

-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Create New...