by "Textured Soy Protein" (texturedsoyprotein)
Published 09/25/2017 at 15:19
by "Textured Soy Protein" (texturedsoyprotein)
Published 09/25/2017 at 15:19
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STARS: 4
After my fun Saturday afternoon bombing around some twisties was interrupted by limp mode , I had my car towed to my mechanic. He called me this morning with (relatively) good news! I’m less antsy now.
I have to say, I’m damn proud of how I’ve set up this car. I picked all the mods myself, and the way it accelerates, turns, shifts and stops is just great. Until I upgraded the brakes, I hadn’t really truly bombed around some back roads, and well, this car has very high limits. Probably too high for some doofus like me to be throwing around on back roads.
I love this car, but I don’t love riding in tow trucks with my non-functioning car on the back of them.
Turns out, all of the myriad electrical faults, which included the mass air sensor, turbo diverter valve, both VANOS solenoids, both cam sensors, and the oil pressure switch, all run through a
junction box
behind the glove compartment.
My mechanic traced the lack of signals to this junction box area, and checked all the wiring, relays and connectors going into and out of the junction box. On the plus side, they’re all intact. On the minus side, that means the junction box itself is bad, and needs to be replaced.
He ordered a new box, and it should arrive tomorrow. All told this should cost somewhere in the range of $600-800.
Honestly, I’m still relieved that’s all it’s costing me. I had a feeling with the sheer number of codes, it wasn’t going to be every single one of the damn sensors and instead it was some kind of wiring issue. But still, that long list of codes had me bugging out a little bit, especially because if there was a whole wiring harness required, hoo boy, that could be expensive.
I’ll report back tomorrow once the new junction box is installed and my car is (hopefully!) back to running properly.
"Rico" (ricorich)
09/25/2017 at 15:25, STARS: 0
Hoping that’s all it is! At least it seems to be under $1k all in.
"farscythe - makin da cawfee!" (farscythe)
09/25/2017 at 15:30, STARS: 0
welp.... mechanics are just like doctors.... could be worse is good news
hmmm thats interesting is you’re fucked
"WilliamsSW" (williamssw)
09/25/2017 at 15:35, STARS: 0
Given the huge dump of codes all at once, that’s not too terrible - also great that you’ll get the car back tomorrow!
"diplodicus" (diplodicus)
09/25/2017 at 15:40, STARS: 0
You should open up the old one. I wonder why it failed.
"Textured Soy Protein" (texturedsoyprotein)
09/25/2017 at 15:43, STARS: 1
I suppose I could ask for the old part, but other than touching random parts of it with the cheap multimeter I got as a free gift at Harbor Freight, I wouldn’t know where to begin to test it.
"diplodicus" (diplodicus)
09/25/2017 at 15:52, STARS: 0
You would have to know which pins go to each other and do continuity tests. Unless its something obviously fried on the inside. I can’t find any pictures of the inside online is mostly why I want to see whats in their. I’m guessing its just a circuit board with a few passive components. Either one of those is bad or a bad trace on the board. It’s just weird since it’s inside the car. It’s not like it should be getting too hot like the ABS Modules on the e39s do.
"Textured Soy Protein" (texturedsoyprotein)
09/25/2017 at 15:53, STARS: 2
Thankfully I have a really good mechanic.
"davesaddiction @ opposite-lock.com" (davesaddiction)
09/25/2017 at 15:58, STARS: 0
BMW and their damn sensors... That’s really the only thing that’s given me trouble so far in my car. (knocks wood)
"SnapUndersteer, Italian Spiderman" (dasborgen)
09/25/2017 at 16:04, STARS: 0
Had you considered eBay for a used module?
It can be coded to your car
"Textured Soy Protein" (texturedsoyprotein)
09/25/2017 at 16:04, STARS: 2
Well this isn’t a problem with BMW’s crappy sensors, it’s a problem with BMW’s crappy electrical junction box that lets the crappy ECU talk to the crappy sensors.
"Textured Soy Protein" (texturedsoyprotein)
09/25/2017 at 16:07, STARS: 2
For some goofy electrical box that can render my car undriveable, I’d rather have it warrantied by my mechanic than roll the dice on a used ebay part. Especially since it’s already at the mechanic right now and he can get a new part next day.
"SnapUndersteer, Italian Spiderman" (dasborgen)
09/25/2017 at 16:13, STARS: 0
I understand.... same happened on my 7series and I got a used module.... it worked and I spent 50 bucks
"WilliamsSW" (williamssw)
09/25/2017 at 16:43, STARS: 0
Yep, that’s pretty important with some of these newer cars once they’re out of warranty.
I have a great BMW mechanic, but he’s about 50-60 miles away, and I’ve only taken the car up to him when there’s something major or I have a laundry list.
"AMGtech - now with more recalls!" (amgtech)
09/25/2017 at 17:20, STARS: 1
That’s a good find and sounds like a good price too. Electrical testing and diagnosis are time intensive and can run labor costs up quickly. And the module you’ve got pictured there looks just like a Mercedes seat control module.
"Straightsix9904" (Straightsix9904)
09/25/2017 at 17:24, STARS: 0
How did you diagnose it to a certain junction box? I wouldn’t want to Start picking out $50-100 junction boxes and start throwing them at the car. That could add up real fast. Teach me something!
"Straightsix9904" (Straightsix9904)
09/25/2017 at 17:25, STARS: 0
Good news! Are you running a jb4 on your 335?
"Textured Soy Protein" (texturedsoyprotein)
09/25/2017 at 17:42, STARS: 0
I have my ECU flashed with MHD Stage 2+. I generally don’t like piggyback solutions like the JB4. Especially with how many times I saw people posting about chasing random electrical glitches on their JB4 cars.
At this point with MHD out for the N55 and N54, the only reason to run a JB4 is if you have one of the later N55 cars that requires the ECU to be removed from the car to be unlocked before it can be flashed with MHD, or you want to do something above and beyond the abilities of the stock ECU to control, like converting to port injection.
For basic bolt-ons and cranking up the boost, MHD is a much cleaner solution. It makes wacky wiring issues like this much easier to trace, instead of having a JB4 jacked into all kinds of different spots along the wiring harness.
"Textured Soy Protein" (texturedsoyprotein)
09/25/2017 at 17:45, STARS: 0
This place is a couple miles from my house, in a part of town I’m often in anyway. The one and only BMW dealer in town is 8 miles from me, which is still fine. They charge full BMW parts catalog MSRP on all parts and their labor rate is at least $125/hr. No point taking a car there out of warranty. Sure they have loaner cars but I can share cars with my wife in a pinch. Or just rent something, or uber it. I have options.
"Textured Soy Protein" (texturedsoyprotein)
09/25/2017 at 17:51, STARS: 1
Yeah I’m fine with this price. He told me $390 parts and labor for the junction box, plus the labor for the time he spent diagnosing.
Lowest price I found online for the junction box is $283.95 from FCP Euro and they have it marked as clearance for some reason. Everywhere else is like $340-360.
I’ll take it.
"gmctavish needs more space" (gmctavish)
09/25/2017 at 18:11, STARS: 0
My dads Taurus threw a shit ton of codes like that in 2009. It was eventually diagnosed as a bad wiring harness and bad computer. Also, it was maybe 2,000km past the warranty.....I think that ordeal was about $7500, if you include all the towing, rental cars, staying in a hotel for a week, and flying back to Alberta to pick up the car when it was finally fixed.
"SnapUndersteer, Italian Spiderman" (dasborgen)
09/25/2017 at 19:07, STARS: 0
I just traced the wiring myself due to missing CAN-BUS signal...