[N55Tiger]

Updated on 3rd post, more issues.

Having starting issues with my 2011 E90 335i. For a few months it was having trouble starting, so I had the battery replaced 7 weeks ago. First time in 8 years the battery was replaced and 100,000 miles. Shop said the battery had a bad cell. Started great for a couple of weeks, then about 2-3 weeks ago, the slow start came back. I did some research and ordered a ground cable since it seemed to be a quick fix. Well, the ground cable didn't ship in time and a week ago I was stranded at work with a car that wouldn't start. Turns out the place I bought the ground cable from sent the wrong part, so I still haven't received the cable. I tried jumping it 4 times, no luck. Disconnected the IBS, no luck. I heard the starter click when attempting to start. Got it towed back to my house to troubleshoot, and had to go out of town for the weekend.

Once to my house, I started off with getting the battery charged on a C-Tek charger as I had drained the battery down to ~11.8V. Used a Foxwell scanner, and got the A0C1 code: CAS output terminal 50. Got the battery charged up to ~12.8V, car started up fine. Checked the voltage while running and under load, and it was about 12.9V, disconnected the IBS and the alternator at the battery was putting out about 13.5V.

I plan on swapping out the ground cable tomorrow once I receive it, after that I'm not sure where I should focus my time. Just got under the car, current ground cable is reading .2 Ohms on the multimeter. I've ordered everything to replace the starter, but I'm not sure that is the issue.

With the car not being able to start even when being jumpstarted, I assumed ground cable or starter. Now I'm wondering if I somehow had a draw on the battery that drained it, or if the IBS was malfunctioning and waking the DME and draining the battery. I never saw any battery warning lights since I purchased the car 4 years ago. Or could the tow truck ride have "unjammed" the starter somehow? Anything I'm overlooking?

[N55Tiger]

Bump for any help...

Starter and ground cable comes in today. Going to replace the ground when I get home from work.

I've been needing to change my spark plugs out, so going to do that while I'm wrenching on the car first. Then move on to disassembling everything to get to the starter. Going to check voltage and connections at the starter, but at that point I'm assuming I've done all of the work, might as well replace it.

Just wondering if while I've got the engine bay apart if there is anything else I should look into as a possible cause that's an easy fix in the middle of the job.

Thanks for any suggestions!

[N55Tiger]

In desperate need of help. Changed the spark plugs and the starter. Car goes to start, but runs incredibly rough, dies, or doesn't actually start.

Getting a 29E0 charge air temperature sensor electrical short circuit to positive.

[Jeckolame]

Originally Posted by N55Tiger

In desperate need of help. Changed the spark plugs and the starter. Car goes to start, but runs incredibly rough, dies, or doesn't actually start.

Getting a 29E0 charge air temperature sensor electrical short circuit to positive.

+1

[N55Tiger]

Could I have damaged the crankshaft sensor?

Getting the following codes right after trying to start, but only the 29E0 stays after clearing.

28B0 - Throttle Valve emergency operation mode active
28AB - Throttle Valve potentiometer 1 and 2 double fault
28A5 - Throttle Valve potentiometer 1 electrical short circuit to earth
28A9 - Throttle Valve potentiometer 2 electrical short circuit to earth
2C6F - Charging pressure sensor electrical short circuit to positive
Missed the code - intake pipe short circuit to positive
2FDA - crankshaft sensor signal missing
3429 - Engine oil pressure sensor plausibility too high before engine start
2C58 - Charging pressure control switch off as sequence
303E - Knock control system fault
3847 - LIN/BSD alternator missing
378F - BSD electrical coolant pump missing
3446 - BSD oil condition sensor missing

[WoodE30]

Is it a crank no start, or no crank no start?

[N55Tiger]

Originally Posted by WoodE30

Is it a crank no start, or no crank no start?

The starter is engaging the crankshaft. But it either doesn't start or runs extremely rough. The car is running rich as my whole garage smells like fuel.

[vilord]

I had rough running / running super rich issues when I swapped the starter on my N52, I hadn't properly seated one of the intake manifold gaskets...

If I was in your shoes, I'd pull the IM back out, check all around for wires that might have been crushed or left unplugged, count the number of connectors that are unplugged, then very carefully put it all back keeping a count as I plug things back in to make sure nothing is missed.

Not sure what has to get disconnected on the other side when changing spark plugs on your engine, but I'd do the same over there... basically re-do whatever I did, but double and triple checking the count of things that get unplugged and plugged back in and shining bright lights in to look for crushed harnesses.

[N55Tiger]

Originally Posted by vilord

I had rough running / running super rich issues when I swapped the starter on my N52, I hadn't properly seated one of the intake manifold gaskets...

If I was in your shoes, I'd pull the IM back out, check all around for wires that might have been crushed or left unplugged, count the number of connectors that are unplugged, then very carefully put it all back keeping a count as I plug things back in to make sure nothing is missed.

Not sure what has to get disconnected on the other side when changing spark plugs on your engine, but I'd do the same over there... basically re-do whatever I did, but double and triple checking the count of things that get unplugged and plugged back in and shining bright lights in to look for crushed harnesses.

That's the plan for the rest of the week, been busy and discouraged for the past couple of days, so needed to take a break.

Figured I would re-do all of the labor for the job, and comb over it again. Someone before me cross-threaded a nut on one of the studs for the intake manifold, so I was able to remove the stud and going to replace that this week as well to ensure proper seal. Debating if I should just prepare myself to replace the crankshaft sensor.

I'm thinking the TMAP for the charge pipe is what is causing it to run rich since the code says it is shorting to positive.

Really thankful for the responses. When things go wrong in the car world, it's easy to get discouraged. Just trying to get myself back in the right headspace to tackle this job again.

I followed these videos for both jobs:

Spark Plugs
"https://www.youtube.com/watch?v=MYx-5TImxRM"
Starter
"https://www.youtube.com/watch?v=CbHUjaupm6c&t=1634s"

[vilord]

I totally get being discouraged. After swapping that starter, pulling and reinstalling everything and resolving the rich issue, i still had a check engine light for a vacuum leak... i ended up leaving it for months because i was frustrated.

I haven't made much progress putting my interior back together either, since finding the giant puddle around my battery and the huge rust holes in the hatch :/. Maybe tonight?

[N55Tiger]

Finally had time to get back under the hood. Checked all of the connections once over again and must have had a bad connection, all of the short circuits to positives are gone.

However, now I'm having the A0C1 CAS output, terminal 50 code again and the car won't even try to start. Battery is fully charged. So I'm back at square one with a car that won't start that has a new starter in it. And I know the new starter works since it was cranking after I installed it.

So I've now changed the battery, starter, and engine ground cable. Any other ideas?

[MightyMouseTech]

Check the positive cable near the jump post under the hood. They often fail under the shrink wrap.

[N55Tiger]

My foxwell is reading 10.89V in the CAS at terminal 50 when I'm trying to start the car. Voltage at the battery is around 12.8V.

[N55Tiger]

Originally Posted by MightyMouseTech

Check the positive cable near the jump post under the hood. They often fail under the shrink wrap.

I'll have to check that, leaving town for the weekend so won't get another chance until Tuesday. Thanks for the suggestion!

[Gamb1t]

Wow. Sorry to read about your woes. I'd be bummed too. But don't give up. Be methodical. Hopefully one day it'll come to life and you'll be doing the happy dance with tears of joy.
We'll all be cheering and giving you virtual high fives.

[N55Tiger]

Originally Posted by Gamb1t

Wow. Sorry to read about your woes. I'd be bummed too. But don't give up. Be methodical. Hopefully one day it'll come to life and you'll be doing the happy dance with tears of joy.
We'll all be cheering and giving you virtual high fives.

I appreciate the much needed words of encouragement!

I'm worried when it does crank again it will run rough and die like it did right after I changed the starter. I left the battery on the trickle charger overnight, we'll see if I have any luck on Tuesday to crank it up.

[N55Tiger]

Should I move this thread to the technical forums? New to the site so not sure where is the best landing spot for this topic.

[F31cruisin]

Originally Posted by MightyMouseTech

Check the positive cable near the jump post under the hood. They often fail under the shrink wrap.

So I had a similar start issue. Put new battery, new starter, and both helped for a little, and then the problem came back.

I followed the start signal from the computer all the way to the starter, and all was fine. Then I started following the current from the battery to the jump post, to the starter, all was good. Wanted to shoot my brains out with this damn problem. What I didn't catch, was the drop in voltage when the car actually went to start.

So the power cable from the post to the starter read 12 volt, until you went to crank, it then dropped and wasn't enough voltage to start the car. No way to catch this unless you had the volt meter on that cable when you turned the key. I ended up putting the volt meter on the windshield so I can see the volts while cranking, and sure enough, it dropped way below 12 the second it went to crank. (found this after weeks of the car sitting in the garage)

So I took the cable off the post that went to the starter, and the contact point was corroded to shit. I sanded the crap out of it, exposing the copper, and put on the washers with teeth on both ends, put it all back together, and it started like a fucking champ. Sold the car about 10 months ago, owner still keeps in touch, ZERO issues since then.

[vilord]

Another place that corrodes is under the battery in the trunk, there are big terminals that go through the body of the car and they corrode right there.