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lost control of my heat


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i have two codes they are b 1340 and b 1341 they are for the air movement door motors all the rest of my climate control works ie, fan speeds ac etc there must be a module that controls these doors but i cant figure it out some one out there is smarter than me please help thanks

oh yeah its a 97 deville concours

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B1340 Air Mix Door One Movement Fault

B1341 Air Mix Door Two Movement Fault

These are electrically controlled vacuum servos and they to sometimes go bad, usually through sticking. Most of the time there is a bad vacuum hose. Two of them at once is likely either a vacuum leak or a broken wire, most likely a vacuum hose off of its connector. You can check this by putting the car in Park at idle, pressing the parking brake, and then moving the transmission to Drive. If the parking brake doesn't release in a few seconds, you likely have lost the vacuum for the under-dash servos.

The vacuum hose comes throughthe firewall high under the dashboard on the passenger's side and goes to a programmer, which is a box with five hoses coming out of it that operate the temperature control doors and the parking brake release. Most likely that hose is pulled off the vacuum source fitting that goes through the firewall.

Look in the FSM pages 1B-4 figure 2 for a diagram of the vaccuum hoses and programmer under the dash, 1B-6 figure 4 for the vacuum fittings on the engine side of the firewall, and pages 1C-50 through 1C-53 for wiring diagrams and troubleshooting charts for solving electrical problems with DTCs B1340 and B1341.

-- 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.

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Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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