[Beastiezzz]

Hello all,

Long time member here but it's been a while since I've posted. I have a question that I'll put right at the top and if you want to read how I got here you can. I know if there's anyone on the Internet anywhere that might have the answer it's most definitely someone on this forum. Thanks for reading ahead of time!

I am in desperate need of a company or even just a person who is familiar with repairing the smart junction box from a 2005 Mustang GT Premium. If anybody knows of a service like this I would greatly appreciate the contact info.

This car is extremely important to me and without this Smart Junction Box or Body Control Module (whatever it's actually called) my Mustang is as you probably know, an expensive lawn ornament.

Read below if you want to read the story behind how I got here:

I have an issue with my 2005 Mustang GT that I've owned since new. Over the years I've fixed all the water leaks in my car and then a while back I got t-boned by some moron who ran a stop sign. She hit me right where the passenger door meets the fender.

My insurance company wanted to total the car, that only had 50k on the odometer at the time, and they did. This car means so much to me that I took the money they gave me and had it fixed. When I mean fixed I went around the car and circled every problem and had a brand new paint job. This even left me with some $$ left over.

Last week we had a heavy rainstorm here in NYC and I realized that I had to find all the leaks again because the passenger side carpet was soaked again. This time it was a new one for me. It was the large grommet that gets the wiring harness through the firewall that the body shop didnt seal properly. I took the carpet out and dried it, installed the grommet properly and even sealed it with RTV and made sure all of the other usual suspects weren't also letting water in. After I reinstalled everything, charged the battery, started the car and was about to take her out for a spin only to realize that so much of my electronics inside the car were acting erratically. I realized among the other strange electrical problems that I now had was also a check engine light. I immediately got out my diagnostic scanner (Xtool D8) and it pulled nearly 30 codes just from that SJB.

I now have the circuit board in my house out of its case with a fan on it hoping that its just some water intrusion. The is some evidence of water getting in through at least 2 of the harness plugs but nothing crazy on the board itself. Between all the water and the accident that looked like she was aiming at that SJB I'm guessing it's more than a simple dry, clean and reinstall job.

So with all this said I would really like a professional to test this module and repair it if possible. If you made it here I'm sorry for the long post but I guess I needed to vent.

Thanks again all!
-Rob

 

[Beastiezzz]

All of the pins are still there and have been cleaned already. I'm going to spray some contact cleaner into the harness side to clean them too and let everything dry out well for a few days. Were you thinking of deoxit? That's what i use for electonic repairs and cleaning like this.

Since these units have 'Scrap if Dropped' in huge letters on the case I'm looking for a Pro to take a look. There are tons of circuits and processors on this large circuit board. After 18 years I wouldn't be surprised if something went bad on the PCB.

 

[Beastiezzz]

You could just send your SJB out to be checked by an automotive module service that will both check and fix it if needed. Automotive Circuit Solutions, Autoecm, Upfix, and Module Master are places worth checking into.

Thank you for the company names, that's exactly what i was looking for.

As far as the cowl panel leaks and any other water intrusion in the TSB have been taken care of already and checked to make sure they are not an issue anymore. This grommet should be added to that tsb as well.

Photos are attached to my original post.

 

[Beastiezzz]

You could try 1 of the pcm rebuilders, don't remember why but had this one bookmarked.

Engine Control Modules | ECM | PCM | ECU

Flagship One is your trusted source for updated and pre-programmed engine control modules and module repairs. FREE LIFETIME WARRANTY & FREE SHIPPING. Shop Now!

www.fs1inc.com

Thank you!

 

[Beastiezzz]

CJ’67 has a point maybe module is not capped over at all. Look for very tiny “poof” marks tracing circuits along then also printed board itself on backside. Only once I found this- Ribbon cable “Not polarized” would plug either direction. Strange thing it somewhat worked one direction and other the way it should. This was on a King-Fisher fire alarm receiver printer (radio transmission). Very high-end, would never even think to question company.

Just noted photos, looking over for plug-in IC chips, same difference. Look closely both sides at exterior edge around card. Appears corrosion, shorts or even breaks in ribbon. Maybe just photos?

I have looked over the ciruitry as i have some experience with IC repair but this is a little beyond something i can handle. I couldn't find any bad traces on the board anywhere but the large chip on the top left looks like it may have overheated enough to make the epoxy coating bubble up.

I'm going to contact some of the repair companies listed above when I get home in a few hours.

I will keep y'all posted. Thanks for all of the fast replies 🙏

 

[Beastiezzz]

So after drying out the SJB for 2 days, cleaning all of the corroded pins and harness plugs I reinstalled it today.

I cleared all of the trouble codes that were stored in the car and went for a drive. I didn't see alot of the weird electrical issues i was having before this and the car is driving great like usual.

When i got home i scanned for trouble codes again and this time the SJB only had 12 this time. None of them were enough to trip the check engine light this time.

I still may send this module out to have a pro test it out and see if they can find any issues.

In the meantime i have an issue that I'm not sure is even controlled by the SJB. While waiting for the scanner to do its thing, i had the key on and engine off. For no reason at all I stepped on the go pedal and when I did I heard a buzz under the hood and then tapping noise. I don't remember this happening before but this noise was coming from the throttle body as the throttle plates opened and closed with the gas pedal.

Is this normal operation for the throttle body to actuate even with key on engine off or do I have an issue there?

 

[Beastiezzz]

Some electronic throttle bodies will do a sweep even with the engine off. It is discussed at the 2 minute mark in a video about safely cleaning a throttle body.

That's interesting, i have always taken the throttle body off the car to clean it.

My throttle body is reacting whenever the key is on and I step on the pedal. It is acting as if the engine is running and i have full control of throttle input. It's possible that i have never heard this before but I'm just not sure. After driving this car for almost 18 years I feel like I would have heard this before.

 

[Beastiezzz]

Only 12?
I would have it sent out to a reputable module service and have them test and fix it.

12 was down from nearly 30 the last time I scanned it. I am waiting for a call back to have someone possibly take care of this.

 

[Beastiezzz]

If it does it a single time when you step on the pedal then that might be ok but if it does it again multiple times in succession every time you step on the pedal then that's definitely not normal.

That's exactly what i was thinking

 

[Beastiezzz]

Hopefully your issue is (mostly) resolved. But make sure you have sealed all the water entry points. 1) I removed the rubber drain flaps below the windshield cowl that would sometimes get clogged and allow that area to fill with water and enter via the cabin air filter - no chance of clogging now. 2) I also ordered/installed a replacement set of the heat sealing tab sockets that the tabs of the plastic cover under the wipers insert when being installed. 3) I replaced foam sealant strips under the plastic trim around the upper door frames. 4) (In case all that fails and there is still a leak) I wrapped a clear plastic sheet of plastic over the top, back and front of the BCM/SJB which should keep water from getting into the box/electronics.
ALSO, Don't be afraid to buy a used BCM/SJB - as long as you: 1) make sure the numbers match exactly what you have now. 2) You buy it from a source that ideally tests it AND allows returns if it doesn't work. That's what I did (via ebay no less) and it has worked perfectly without any new programming. It felt risky but the $250 was much less than the $1,000+ the Ford dealer wanted for a new one and programming. BEST OF LUCK!

Thanks! I have gone through and sealed all the places you've mentioned. I also removed those rubber "Drains" that they put in to apparently catch debris as well as the flaps on the cowl panel drains after the first time my floor got soaked through the cabin air filter opening. I think I will build a protective coverfor the SJB, like you have, just in case water somehow makes it back in.

The car is running great now since I reloaded my custom Lito tune since reinstalling my SJB. I think in the process of removing it I may have confused the electronics in the car. It seems that the SJB is now doing its job along with the PCM as I now have 0 trouble codes. I think removing it, drying and cleaning all the bad connections may have saved me from having to send it out for repair.

The only thing that is strange is the throttle body issue I had mentioned. I was hoping if someone would be kind enough to possibly check the function of theirs, that would really help me out.

Key on engine off and step on the gas pedal with the hood open to hear if your throttle plates move with your pedal input.

Any help would be greatly appreciated on that one 🙏

 

[Beastiezzz]

Actually it is normal for the pedal to signal the TB with key on/engine off. Holding the pedal down after a timing job or even an oil change is an easy way to prime the oil system as it puts the PCM in to safety mode and will not allow the engine to start. This is also how you find "dead spots" in the throttle position sensor and/or pedal sensor. Some people diagnosing TPS issues by themselves will usually put a full length mirror or such in front of the vehicle so they can watch the throttle blade sweep as they gradually press the throttle pedal. The clicking sound under the hood is the throttle blade going to the full open position if you mash it to the floor instantly.

Thanks for clarifying. It looks like I might be out of woods then🤘