Cadillac Seville / Cadillac Eldorado Forum Discussion, codes in Past Cadillac Vehicle Discussion; Can someone please tell me what these codes mean or where I can find their meaning. DDM U1713, IRC U1064 ...
Go to the thread at the top of the main Seville page "How to pull codes". Read the whole thread, then go to the link with "obd2" (OnBoard diagnostics protocol -II) in the url. Click on the lines in the main index box to decipher the P,B,C, and U codes. Bookmark the link - you'll need it.
Do NOT clear codes now, just note whether they are Current or History - it makes a difference. If you clear the P (PCM) codes the car will not pass emissions testing for a couple of weeks until the system settles out.
U codes are usually data transmission and voltage comparisons and come and go like the clouds. Other codes will show as Current if a fault exists, will go to History if the fault does not occur for 3 successful start-run cycles, and will disappear entirely after 30, 40, or 100 such cycles, depending on module.
You need to Google a list of GM part and module acronyms or get the acronyms from the introductory pages in a GM/Helm Factory Service Manual.