This is stuff I've never seen before. Car is a 2002 SE 6 spd.

It starts with the door locks and windows. They haven't functioned properly for a couple of months now. Sometimes they work, sometimes they don't. Fob won't roll windows down anymore. Sometimes the one-touchs work, sometimes they don't. Sometimes you go to one-touch up, and it goes down. Sometimes it works fine. Over the months I've had these problems, I have definitely noticed heat is a factor. On hot days when the car sits in the sun, they are more evident.

However, I read a thread from a couple years back that lead me to believe the culprit for this is the SECU (the computer for the comfort electronics). Now this is where it starts getting baffling...

Two days ago I got in my car and tried to change the cd. I hit the open button on my aftermarket head unit, and it wouldn't budge. The screen read "open" as it always does, but the unit did not slide out and eject the cd. After a few seconds it just continued playing the cd that was in there. My initial thoughts were that the unit itself was busted. However, after several trips in the car listening to this one stupid cd, I went out later the next day to go to my sister's house, and thought I would try the cd again. I hit the button hoping it would work, but no dice. I got frustrated and hit the button twice fast, and woila! It worked. BUT... no sooner had that happened than my blower fan stopped working. No A/C, no air, no nothing. Displays work fine, compressor starts if I put it on Auto. Everything indicates that the air is running, just nothing coming from the vents. My windshield fogged up on the trip home, so I put the defroster on and that worked fine. It actually cooled the muggy car down a bit and made it more comfortable, but the dash vents are dead.

So, yesertday morning I take the car over to my brother's so we can take a look at it. Pulled the stereo out and the climate control, and started looking around. Nothing seemed out of place, but the head unit stopped working entirely. While we had it removed (but everything plugged in) every time we hooked the power up it just clicked. Wouldn't turn on, wouldn't play cds, wouldn't open. Just click. Mind you this whole unit is aftermarket. We looked at fuses, checked for power in the power and memory wires, and everything checked out fine, but the whole unit wouldn't do anything but click. So we removed it and switched it into his car (he already has an apline setup, so it was easy to just pull the box and plug in a different one, everything was compatible). Hit the power button, everything works perfectly. Switch back into my car... click click click. Frustrated, I just gave up. Makes ZERO sense. The only thing the unit should need is power and then run on it's own. Took everything, put the dash back together, and whoila. The stereo is working fine again. Nothing new, or different, just put the screws in to hold it in place.

The blower, on the other hand, is still not working. This electrical gremlin in my car is really starting to get on my nerves. The ONLY idea I have right now is the SECU, but I have never read anything about the SECU causing the blower to fail, and I can't see how it would have an effect on an aftermarket stereo. I'm no electrical genius, however, so I'm appealing to you guys.

Could the SECU be responsible for ALL these problems (door locks, windows, head unit, blower), or is it likely something else? Perhaps the SECU and the blower too? I've checked all the fuses. Anyone have any ideas?

 

No, it needs a ground. When you pulled it out of the dash it lost its ground from the chasis. Im not sure about the other issues.

 

Sorry, I forgot to mention that, it was grounded. We made sure of it. If it wasn't grounded it would have received no power and wouldn't have clicked like it did.

I appreciate the reply, nonetheless.

Any other ideas?

 

I would almost venture to say that the SECU may have popped some cold solders. If you can try replacing it. Either that or maybe an improper installation of the head unit may have fried it. Unfortunately I have no schematics for the car so I can not trace the fault.

 

I would check the battery, alternator, grounds, etc. before getting a new SECU.

 

The grounds and fuses are all fine. I didn't think of the battery or alternator, simply because if those were the cause the problems would have gotten worse or more pronounced, and surely after months I would have seen more problems than door locks and windows? I suppose it's worth at least checking all the same though... appreciate the input.

Any other ideas?

 

No other input? Does anyone have any suggestions on how where to go to have this figured out, other than the stealership? Anyone who knows something about all this that I could contact?

 

Question: Is there a diagnostic for the body computer or is that just for engine management? Only reason why I am hammering on this is because I know Audis have a similar defect. It was very specific on what it did too. A neighbor of mine had a TT that at 1:25 AM it would lower the windows pop the door locks and set off the alarm every night.

 

They SECU and the ECU are different entities, this much I know. I do not believe there is any diagnostic tool that can be used to scan the SECU for errors or problems. Wish there was. I could be wrong though, my knowledge on this is not overwhelming, hence why I'm seeking someone else knowledgeable.

 

id go get your alternator checked at an advance auto parts/autozone and make sure it is putting out the correct voltage, kind of off the wall but when they start overpowering it does weird stuff

 

Is the yellow wire hooked up to 12V via noise suppressor and the red to a switch of some sort ie...factory radio or ignition? I assume that you have the black wire grounded close to the HU. Is it a clean ground? Have you tried swapping your brother's unit into your car? With you FOB situation have you tried it with head unit out? Are any of the wires pinched or laying across bare metal? Something may be grounding. Another place to look is the relays. They may be loose or going bad.

 

I appreciate the response!
First, we inspected all the wires for possible grounding. The yellow (power) wire produced a good signal showing that there is power running through it as intended, as well as the red (memory) wire. I thought of the relays, but if a relay went bad, and I'm not sure, but my impression is that something would stop working altogether, rather than sometimes work and sometimes not. Also, heat is a definite factor, while the effects are unpredictable during 60-70 degree weather, those hot days with the black leather interior heat the car up to 95+ degrees in the cabin, you can be sure the effects will be present. This is also not indicative of a relay problem. Also, the blower seems to have ceased completely. I can't get it to work at all, which now seems seperate from the other problems as they are not constant problems. I'm thinking I may have no choice but to bend over for the dealer...

 

relays can come in and out, sometimes they stick, etc

 

So I decided I have to bite the bullet and go to the dealer. Gave them a call and described the problem, they made an appointment next week. I asked them what to expect for the diagnostic, and they want $180!!! Just to look at the freaking thing. I don't know what to do, I'm thinking I might have to just cancel the appointment and deal with no air conditioner and these random problems. If they want that much just to look at it, nevermind whatever they'll end up replacing that I don't need. I'm at a loss for words here. Does this seem ridiculous to anyone else? Should I just try and replace the SECU myself to see if it works? I can't afford an $800 repair right now, and there's no telling how high the stakes will go when they're telling my 200 off the bat just to figure the problem out.

(Sorry, first time having to go to a dealer for anything).

Is this normal?

 

sounds about right for the stealership man...