Cadillac Electrical Problems +

Tiny
LANDON PARKER
  • MEMBER
  • 2000 CADILLAC DEVILLE
  • V8
  • FWD
  • AUTOMATIC
  • 146,000 MILES
I have a 2000 Cadillac De Ville that has developed a few electrical problems. All fuses have been checked.

#1 Drivers seat automatic and manual functions quit working. The seat heater hasn't worked since I bought the car used.

#2 Cruise control stopped working. You can hold down the steering wheel button and the light comes on and the cruise works if you keep holding down the button. If you release it the cruise quits.

#3 No heat in rear seat vent system.
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Monday, July 11th, 2011 AT 5:40 PM

7 Replies

Tiny
FACTORYJACK
  • EXPERT
#1 could be an issue with logic lock of the memory seat module, since all seat functions go through it. You can either disconnect the battery cables and short(touch) them together for a minute or so, or remove the power to the module by removing the power seat circuit breaker in the rear fuse block. Do the power mirrors/tilt wheel function, even when a memory button is pressed? The seat heater is another story, these vehicles had issues with the seat heater elements, so much so that there was a service bulletin on the matter.

If you have to press on the power button and hold it to get the cruise to function, but when you let it off the LED goes out, the switch appears faulty.

And on the rear heat, is it an issue with no blower, or is there no warm air?
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Monday, July 11th, 2011 AT 6:37 PM
Tiny
LANDON PARKER
  • MEMBER
Did the trick with the battery cables and it fixed the seat adjustment problems. Thanks a lot for that one. Really uncomfortable driving in the position in which it was stuck.

The rear seat blower works fine and functions with the A/C. Just doesn't produce heat.

Thanks
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Wednesday, July 13th, 2011 AT 8:54 PM
Tiny
FACTORYJACK
  • EXPERT
It is all produced through the same core, there is no auxiliary. I would suspect an auxiliary blend door actuator at this point. This being a 2000, you have on-board diagnostics at your disposal, at least to read codes. If you turn the key on, and press info up and on-off buttons, after a few seconds all the VF segments will light. After the segment check, it will read ALL? On the info center. Press on/off again and it will read ALL CODES. Press on/off again, and record the codes, and repost. I can't remember what auxiliary HVAC codes are stored in, as far as a module, so report them all. You can do it as many times as necessary, just turn the key off, and re-enter diagnostics when you need to.
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+1
Wednesday, July 13th, 2011 AT 10:17 PM
Tiny
FACTORYJACK
  • EXPERT
There is more information I can add. The codes are going to be stored in the IPM(instrument panel module). You should see something like B0428/429. After you process the request ALL CODES, the modules will report in alphabetical order. Coincidentally, before I went home tonight, I got a 2005 Deville with warm air only out of the auxiliary(rear) vents. It had a current B0429, and I am going to recommend actuator replacement.
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Thursday, July 14th, 2011 AT 2:36 AM
Tiny
LANDON PARKER
  • MEMBER
Mine showed a IPC Bo429.

Thanks again for your help.
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Friday, July 15th, 2011 AT 4:46 PM
Tiny
CADIEMAN
  • MEMBER
Possable bad seat switch. Check your voltages to be sure. Your heated seat elements are faulty common problem.
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Friday, July 15th, 2011 AT 5:56 PM
Tiny
FACTORYJACK
  • EXPERT
I replaced the actuator, and that corrected the rear HVAC concern of always warm. The way the actuator is listed on the dual zone system is left and right, there is no auxiliary listed, this is why. The right actuator operates two shafts, one for the RH blend door, and one for the auxiliary blend door. It wasn't to big a deal to change, as litle as removing the glove box, and the actuator is held on with two 5.5mm screws.
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Saturday, July 16th, 2011 AT 2:04 AM

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