[GregC_TX]

Our 2011 335i failed to start after running fine prior to my wife turning the vehicle off at the grocery store back in August. We had the car towed to our local independent BMW repair facility with an initial repair estimate of $1700 for a new starter and fuse box. Unfortunately this did not resolve the no start issue.

Further diagnosis revelaled that the automatic transmission controller on our vehicle also requires replacement, PN 24 34 7 647 856. This is a very expensive component of the transmission, $4147.95 USD as listed on our repair estimate from the shop and is currently a major stopping point to having the car repaired. There are a few alternative sources for this part using a core swap out but the price will still be no less than around $2,500, at best. The vehicle has around 87,000 miles on the clock and is in good shape but the total repair bill for the AT controller, starter, fuse box and labor will push the total to around $7,500 with tax.
I do not know which fault codes are stored, however the repair shop was leaning towards an issue with the transmission prior to contacting us with the repair estimate. We experienced no issues prior to the no start issue with our transmission.

Is this a common part to fail on the e92? Is the car worth fixing or should we pay for what we owe the shop and cut our loses? The car will not start in it's current state and would need to be towed (another expense) and stored someplace (again, another expense unless we store it in our garage) until we determine how to best part with the vehicle. We really like the car but this may be the final straw in our BMW ownership experience.

[NZE90]

It sounds like they are just firing parts at the car and hoping for the best. If it were mine i would get it out of there ASAP, they have no clue what they're up to.
Im an ex BMW technician and while i have seen a few trans failures i don't think any of them were due to the ECU failing. The ZF transmissions in your car are normally very good. Without more information or fault codes it's hard to say what's wrong with your car but i would definitely get the car out of that shop ASAP.

[fastboatster]

This is a plain highway robbery, it’s going to be less to put another used trans into the car rather than getting a new TCM or pulling a used tcm from another used transmission. I second the advice to get the car out of that shop.

[gbalthrop]

Originally Posted by GregC_TX

Our 2011 335i failed to start after running fine prior to my wife turning the vehicle off at the grocery store back in August. [THREE+ Months ago, you had it TOWED to a $hop, and are just now posting? Life is "Busy/Busy".] We had the car towed to our local independent BMW repair facility with an initial repair estimate of $1700 for a new starter and fuse box. Unfortunately this did not resolve the no start issue.
Further diagnosis revelaled that the automatic transmission controller on our vehicle also requires replacement, PN 24 34 7 647 856. This is a very expensive component of the transmission, $4147.95 USD as listed on our repair estimate from the shop...

You need a "2nd opinion" based upon:
1) Fault Codes;
2) Diagnostic Testing with INPA/ISTA (beginning with CAS Terminal Status);
3) Simple reporting of symptoms and what does NOT work as it should (DETAILS), such as when you move the Shift Lever from Park position with Ignition ON and Foot on Brake Pedal, does the Gear Selected appear in Lower Instrument Cluster display, and change with Shift Lever Movement?

Since the $hop charged you $1700+ for stuff NOT needed and NOT related to "No Start Issue", I trust you are able to "convince" them to share ALL diagnostic testing & results of same, both BEFORE & AFTER Starter replacement???

Get that information from $hop and post it here. At LEAST, get them to send you a jpg or pdf from SCAN of their RECORDS of what was done on your car. WE, or anyone trying to HELP, NEED that DATA. If $hop will not, or cannot, provide that, then see if there is anyone in Plano area with a Laptop with INPA or ISTA installed, and a K+DCAN Cable, who will go wherever vehicle currently is located, and connect to vehicle to get data.

Let's start with FIRST simple DETAILS:
When the car would NOT start in Grocery parking lot, did Starter NOT crank engine at all? Was there any "Click" when START button pressed, and if so, WHERE did it seem to come from? WHAT Diagnostic Software (INPA/ISTA) did $hop use to try to DIAGNOSE the issue, WHAT specfic tests were conducted, and WHAT were the findings/results of any such TESTS???

The ONLY thing I can think of related to the Transmission that would PREVENT the CAS Module from Activating the Starter (Terminal 50 Start Signal to Starter Solenoid) is the LACK of P/N (Park/Neutral) Shift Lever position message via PT-CAN Bus from Transmission Module to CAS Module. That's like a safety-switch to prevent engine start in any other gear. Connector issues at the Transmission, OR even a broken wire at the Shift Lever can cause a NO Crank issue. I've NEVER heard of EGS Module itself causing NO Crank.

INPA (used by someone who knows how ;-) IN < 5 MINUTES, would tell you if that P/N Shift Lever Position message is being received by CAS Module, from EGS Transmission Module, along with Brake Light Switch Signal, also needed BEFORE CAS will Activate Starter. OR you could have an issue with the wiring/connectors anywhere in that system. This is NOT brain surgery, but it DOES require the ability to follow a wiring diagram, and be able to use INPA/ISTA.

If you have 3 or 4 hours of your own time you can spend on this, and have a Windows Laptop, for the princely $um of $50 for BimmerGeeks K+DCAN Cable, and FREE INPA Download/Install, YOU can actually get the needed data. I or other forum members can provide details. OR, if the $hop has INPA/ISTA, I can suggest what screens to view and save to properly diagnose.
George

[Bmw1939]

Well, they were wrong the first time... Fool me once.....

A simple $20 Bluetooth OBD2 scanner along with the free phone app bimmer-tool would give you the error codes. ISTA is better, but may not be an option for you.

It sounds like you don't work on your car, but you could easily scan it so you know what the computer is saying and go from there. People here would help you diagnose the problem.

Find the cheapest tow truck service in your area as you may be hauling it a couple more times.

George has offered to help you. He is as knowledgeable as anyone on these systems.

[turbohugh]

Originally Posted by GregC_TX

Our 2011 335i failed to start after running fine prior to my wife turning the vehicle off at the grocery store back in August. We had the car towed to our local independent BMW repair facility with an initial repair estimate of $1700 for a new starter and fuse box. Unfortunately this did not resolve the no start issue.

Further diagnosis revelaled that the automatic transmission controller on our vehicle also requires replacement, PN 24 34 7 647 856. This is a very expensive component of the transmission, $4147.95 USD as listed on our repair estimate from the shop and is currently a major stopping point to having the car repaired. There are a few alternative sources for this part using a core swap out but the price will still be no less than around $2,500, at best. The vehicle has around 87,000 miles on the clock and is in good shape but the total repair bill for the AT controller, starter, fuse box and labor will push the total to around $7,500 with tax.
I do not know which fault codes are stored, however the repair shop was leaning towards an issue with the transmission prior to contacting us with the repair estimate. We experienced no issues prior to the no start issue with our transmission.

Is this a common part to fail on the e92? Is the car worth fixing or should we pay for what we owe the shop and cut our loses? The car will not start in it's current state and would need to be towed (another expense) and stored someplace (again, another expense unless we store it in our garage) until we determine how to best part with the vehicle. We really like the car but this may be the final straw in our BMW ownership experience.

I'd be very surprised if the TCU caused a nostart condition, unless there's a problem with the gear position detection. I would go to a BMW shop that has the proper understanding of reading the BMW specific fault codes. The starter and other repairs they have done were likely unnecessary. Don't let them start firing the parts cannon at your car, dispute their original analysis and get your car away from them as soon as you can before they mess it up.
Just my opinion [but I have seen the parts cannon approach go very wrong , especially with a car that requires specific tools to correctly diagnose]. You literally could have a broken wire in the gearshift console causing this.

Someone else had this issue on the forum ..Try this test :

"
- put Remote Key in insert compartment, and press START button WITHOUT pressing Brake Pedal (just turn on ignition), can you then press Brake Pedal and shift from Park to R, N or D? Does Gear selected appear on the Lower display of the Instrument Cluster? (P, R, N, D?)

If the "Gear Light" LED beside the shift lever changes when Lever is moved (as it should), BUT the display of gear selected on lower Instrument Cluster does NOT move, then the CAS Module does NOT receive the P/N gear position needed to allow activation of the Starter, and there is NO Crank/ No Starter Activation (KL50) by CAS.
"
There is also a fuse or two/3 for the TCU .
Wire break can cause this. there are some wires under the gearshift boot as well as on the transmission , if they break you get no-start/no-crank-/no-CAS->TCU loop. Get your car to a better place friend.

Oh and maybe try to pm a user here named 'gbalthrop' : Credit to him because a friend of mine had an issue with his X5 and it was a fuse due to a wire shorting. We fixed the wire and swapped in a fuse and back to normal in an hour.

Good luck.

[GregC_TX]

Thanks to everyone who responded to my post. It seems that the shop is indeed guessing at what's wrong and throwing parts at the problem instead of trying to accurately diagnose it. I have worked on many of my cars in the past but due to changes in my family situation those days are now gone. It's not as if I'm not capable but the family doesn't exactly allow time for such.

I think I'll cut loses, pay what we approved them to do and have the car towed somewhere else.