Check Engine Light on 1986 Fleetwood Brougham

Lord Fleetwood · #1 (**permalink**) 09-01-09, 06:36 PM

I just bought a 1986 Fleetwood Brougham d'Elegance. I got it for $800 with the purpose of fixing it up (it needs some TLC). I've fixed a bunch of things on it, but the persisting problem I have is that the check engine light comes on. On other Cadillacs I have owned or helped others fix, holding "off" and "warmer" on the climate control would call up the computer codes, but on this vehicle I cannot get this to work. My major question is: Does "off" and "warmer" call up the codes on this vehicle, and if it doesn't, is there a way to do it?

The only noticeable problem with the engine is that it revs way too high when I start it when it is cold. If I wait a little while and then quickly depress and release the pedal a few times, the idle will come down to what sounds normal. Upon driving it, though, the check engine light will come on after some time. I would think this problem and the light are related and being able to check the codes would help me start diagnosing the problem, but I can't get to the codes! The car is carbureated and has the Olds 307 in it. I've checked all of the vacuum hoses (and reattatched one or two that were not on) and all seems in order. I tried replacing the climate control dash control, the computer, the climate control computer (the device that controls the heater door behind the glove box), and what I think is the blower control chip (this is under the hood). None of this changed anything. The reason I did all of that climate stuff was because another issue I have is that the air conditioner will only blow cold when the climate control is set to max cold (auto and 60 degrees) and I thought maybe it was a climate module problem that was also keeping me from getting the codes since they both use the climate control to display. After all of this neither the engine problem or the AC problem have changed at all. If anyone could help me with this, I'd be very greatful.

Stingroo · #2 (**permalink**) 09-01-09, 06:49 PM

Sven will be your new best friend. He's got a 307 Fleetwood and knows all of that good stuff.

sven914 · #3 (**permalink**) 09-01-09, 08:46 PM

To pull codes from a 307 equipped Cadillac, you have to jump the terminals on the ALDL connector, which is under the center of the dash. You have to insert a paper clip into the last two terminals (going toward the passenger side) on the top row. After the paper clip is in, turn the ignition to the "run' position, but DO NOT start the engine. The check engine will begin to flash out a two digit code. The first code will be 12 and will be presented as 1 flash/pause/ 2 flashes. Follow this link for a complete list of codes.

The engine going to a high idle when you start is normal when it is cold (and only when cold). It is called the fast idle cam, which helps the engine warm and keeps it from stalling in cold temperatures. The idle should go to normal with one quick jab of the throttle, but it takes a little practice to hit it just right on the first time.

csbuckn · #4 (**permalink**) 09-02-09, 03:09 AM

your AC will be on constantly at 60. You have to set it to 65 for it to really be in auto(clutch turns on and off). One quick question...I have to get to my heater controls also, are all the controls behind the glove box?...like the valves and vacuum hoses?

RocketFast321 · #5 (**permalink**) 09-02-09, 05:11 AM

If its like my 84 electra, it's a motor that opens and closes a door to the heater core. Lord F/l as for lights coming on when dirving, these things come to mind. Oxygen sensor, and VSS. The O2 is a $20 and I would just install a new one. Who knows how old the one in their is.

Lord Fleetwood · #6 (**permalink**) 09-02-09, 07:09 AM

Quote:

Originally Posted by csbuckn

your AC will be on constantly at 60. You have to set it to 65 for it to really be in auto(clutch turns on and off). One quick question...I have to get to my heater controls also, are all the controls behind the glove box?...like the valves and vacuum hoses?

Yeah, I know it isn't really auto unless it is 65 or higher, but the only way the AC will blow cold in the cab is if it is set to one of the autos (low, auto, or high) and 60. As soon as I put it up to 65, it will blow a small amount of heat out instead of cold despite the fact the compressor will turn on and off like you said. It seems like it might be a heater door, it is just the only one I could find is attached to a motor behind the glove box and it seems to work fine (it will move gradually as a lower or raise the temperature from open to closed). I haven't found another yet.

As far as what is back there, it would seem that most of it, if not all of it, is back there, as far as motors, valves, and hoses go. If you remove the glove compartment (a matter of 4 screws), you will be able to see the climate computer that controls the heater door on this left behind some wires. It is a long black boxy item taller than it is wide and it will be held by three screws (7mm heads if I recall, a popular Caddy size). Two things hook to it, a wire harness that goes to the computer chip, and a bunch of vacuum hoses in a rubber plug. A nut holds on the rubber plug (1/4" I think). You can follow some of the vacuum hoses, but some went farther than I was trying to get to, so you might need to go farther than I did to get to the end of them. If some go through the firewall out to the hood I do not know, but they didn't seem like they did. The only part I know of under the hood besides the AC items is a blower control chip. It is right on top on the passenger's side by the wipers and has a wire harness go to it and a ground wire. Two screw hold that in and it is really easy to replace. I had a 1983 Coupe Deville that had a bunch of heater problems and these items were the only ones I ever needed to replace. This car seems to have the exact same set up as my old Coupe Deville. Hopefully that is helpful to you. If I could help you more, just let me know.

Lord Fleetwood · #7 (**permalink**) 09-02-09, 07:20 AM

Quote:

Originally Posted by sven914

To pull codes from a 307 equipped Cadillac, you have to jump the terminals on the ALDL connector, which is under the center of the dash. You have to insert a paper clip into the last two terminals (going toward the passenger side) on the top row. After the paper clip is in, turn the ignition to the "run' position, but DO NOT start the engine. The check engine will begin to flash out a two digit code. The first code will be 12 and will be presented as 1 flash/pause/ 2 flashes. Follow this link for a complete list of codes.

The engine going to a high idle when you start is normal when it is cold (and only when cold). It is called the fast idle cam, which helps the engine warm and keeps it from stalling in cold temperatures. The idle should go to normal with one quick jab of the throttle, but it takes a little practice to hit it just right on the first time.

Thank you so much for this information, Sven. It worked and I got code 21, which apparently deals with the throttle position sensor. I'll get on that once I have some sunlight to work with.

I also appreciate the information about the fast idle cam. It is nice to know that the high rev is normal, though sometimes it still takes me a few hits to get it down. Practice will make perfect, at least I hope. The engine will do it a little sometimes if I only go a very short distance and put it back in park, but it never does it when warmed up, so thanks to your information I will take this as normal operation. I'm too used to fuel injection, but I'm learning. Thanks again!

Lord Fleetwood · #8 (**permalink**) 09-02-09, 07:25 AM

Quote:

Originally Posted by RocketFast321

If its like my 84 electra, it's a motor that opens and closes a door to the heater core. Lord F/l as for lights coming on when dirving, these things come to mind. Oxygen sensor, and VSS. The O2 is a $20 and I would just install a new one. Who knows how old the one in their is.

Thanks for the advice. Knowing that car I wouldn't be surprised if everything you mentioned needs replacement. Just doing basic tune-up items so far have made it run a hundred times better than when I got it. The car just needs a little caring...a diamond in the rough it is.

Lord Fleetwood · #9 (**permalink**) 09-02-09, 07:30 AM

Another side query: The vinyl top on this car was not well taken car of and it bears a lot of bad cracks. I am more than willing to undertake putting another top on it (I couldn't make it worse) and I have read a bunch of literature on the subject, my issue is I can't find where to get a new one to install. I looked online and couldn't find anything. I even asked a body shop, but they told me they didn't do tops and didn't know. Anybody know where to get a new one??? The body is in such good condition for its age I'd really like to have a vinyl top to match.

Stingroo · #10 (**permalink**) 09-02-09, 08:15 AM

Try an upholstery shop. That's the only thing that really comes to mind here. Otherwise, I just don't know.

csbuckn · #11 (**permalink**) 09-02-09, 11:23 AM

Maybe a climate control door is sticking, the interior temp sensor is reading off, low coolant or maybe the car runs a little hotter than it should(wrong therm)? This would make extra heat.

RocketFast321 · #12 (**permalink**) 09-02-09, 02:22 PM

I would like to know alittle more about this heater door. My motor that controls it is busted. It moves back and froward a little, then temp like starts flashing on my climate control. I had to run a wire thru the dash to open and close it.

Lord Fleetwood · #13 (**permalink**) 09-03-09, 03:32 PM

Quote:

Originally Posted by csbuckn

Maybe a climate control door is sticking, the interior temp sensor is reading off, low coolant or maybe the car runs a little hotter than it should(wrong therm)? This would make extra heat.

Coolant and thermostat seem fine, though I am going to replace the thermostat anyway (just haven't gotten to it yet). I thought of a climate control door, but I can only find one and that works fine. If there is another, I don't know where it is or how to get to it. Also thought of the internal temp sensor, but once again, I do not know where that is. I got a picture of it from a parts website (which I hope is accurate) and went hunting for something that looked like the picture, but have yet to find it. Diagnosing this problem has put me on a hunt for parts, so I just need some locations.

Lord Fleetwood · #14 (**permalink**) 09-03-09, 03:41 PM

Quote:

Originally Posted by RocketFast321

I would like to know alittle more about this heater door. My motor that controls it is busted. It moves back and froward a little, then temp like starts flashing on my climate control. I had to run a wire thru the dash to open and close it.

Do you have a good junkyard near? I do and not only are climate parts cheap (that blower motor door control in my car was like $10) but over the years I've never gotten a climate part that didn't work (though one did break a year later one time). Getting from a junkyard is always risky, but people don't typically get rid of cars because of climate controls and the chances the junked car you'd get a part from had the same climate problem as yours is not too high. I would recommend replacing it with a cheap part from a junked car. The heater door is a simple mechanism, but that motor is all-important in running it with these electronic climate controls.

RocketFast321 · #15 (**permalink**) 09-04-09, 01:16 AM

Quote:

Originally Posted by Lord Fleetwood

Do you have a good junkyard near? I do and not only are climate parts cheap (that blower motor door control in my car was like $10) but over the years I've never gotten a climate part that didn't work (though one did break a year later one time). Getting from a junkyard is always risky, but people don't typically get rid of cars because of climate controls and the chances the junked car you'd get a part from had the same climate problem as yours is not too high. I would recommend replacing it with a cheap part from a junked car. The heater door is a simple mechanism, but that motor is all-important in running it with these electronic climate controls.

Ok now i know Cadillacs have the same setup, just diff. control panels. Our junk yard has a lot of 80s caddillacs, but no 80s Buick electras. i will bring my little mower battery with me to test it.