B1344 is for the mode door actuator which controls vents, defrost, and floor. B1340 means Driver's Side Temperature Actuator has failed which would be the "air mix actuator". B1327 refers to a problem with the Dash Integration Module. If your heat isn't working then the drivers side temperature actuator is the main problem. Here is information for each code from manual. Let me know if there is anything else I can do to help. Thanks.
Here are also replacement instructions.
Okay, so I need to replace the drivers side temperature actuator (air mix actuator). As I said, I have to order it from the US. Would it be possible for you to look on www.rockauto.com (or anywhere) and advise me of the Dorman / ACDelco / Standard Motor Products part number I need (as there are a lot of parts on there and the names are confusing). Could you also confirm if that part will work in a RHD Cadillac. Thank you.
Thank you. You have actually given me the same number for right and left. Is that correct, or is the left side actually 89018375 ? Thanks.