[mastarron]

Hi all,

Car = 2011 328xi automatic-GM-transmission with ~121,000 miles

The car was driving and shifting just fine, I parked the car, and then it would not turn on, but would make contact.

In the "speed cluster" when I shift gears, it does not show P or N. However, when its in N, Im able to push the car, and when its in P the car does not move. I got a tow truck and towed it to a mechanic. My D/S went away about a year ago, so I figured this might be wiring related. We opened the middle console and repaired all of the broken wires, but the car still does not recognize P or N. We removed the entire middle console to see if there are any broken wires, still nothing. The mechanic is looking for another wiring harness to try and rule out this being an electrical issue, before moving onto other Transmission parts.

We ran codes and below is what we got;
Flexible Bus interface;
E147 - Combox Emergency Call, Body controller area network line fault
E150 - Combox Emergency Call, Body controller area network, communication fault
AA0E - CBX-ECALL: Software reset

ABS-DSC
5F2F - DSC: Transmission Interface

VTG Transfer Case;
54C6 - VTG: Oil Wear (I believe this comes on at 100k miles, but please correct me if im wrong)

CAS/FEM/BDC;
A0B1 - CAS: Input, Selector-Lever position, implausible

Those were errors with the code reader, below are errors i see in CIC;
1) AWD and DSC - 4x4 system and DSC have malfunctioned. Limited driving stability. Drive moderately. Have system checked by your BMW service center as soon as possible.

2) Start-off assistance - Start-off assistance inactive Caution, vehicle may roll back! Have the system checked by your BMW Center at the next opportunity.

Based on your guys experience, what should we do? We have since sent it to an Indy BMW guy, who is looking for another wiring harness from a similar vehicle. The fact that the car was shifting perfectly, it doesnt seem possible to me that its really transmission related, but I could be wrong. I changed the ATF about 30-50k miles ago, could it be something as silly as this? OR something as complex as replacing the transmission or bigger(more expensive) components.

In NYC I had a reliable indie shop, but I have since moved and this is my first experience with this BMW mechanic. I have no choice but to trust this guy, since I have nobody else to take it to. But wanted to hear what you guys might be able to tell me from your experiences.


Thanks,
mastarron

[mastarron]

Hey guys,

The car is still in the shop and they dont open until tuesday due to Holiday. But while poking around and reading, to me it sounds like the issue could be transmission range sensor / neutral safety switch. looking at fcpeuro and ecstuning, im not able to find one for my car, what i was able to find is “Automatic Transmission Switch”. Do these parts all serve the same function? Or are they seperate and im just having difficulty finding the right parts? If anybody with good automatic transmission knowledge can help out, I would greatly appreciate it.

Here is the part on ecstuning;
https://www.ecstuning.com/b-genuine-...h/24357581602/

Thank you all!

[rjaudi]

I would buy a used shifter and see if that works if I was in your shoes.

[matteblue3er]

Originally Posted by mastarron

CAS/FEM/BDC;
A0B1 - CAS: Input, Selector-Lever position, implausible

This right here is most likely preventing you from starting

Hard to say if its the shifter assembly but I have an auto gear shift assembly if you want it. $50 shipped or if you want to pick up, I'm in North NJ. The wiring harness was repaired but I pulled it from my car when I did a 6MT swap and it was working with no issues.

[PhaseP]

Originally Posted by mastarron

Hey guys,

But while poking around and reading, to me it sounds like the issue could be transmission range sensor / neutral safety switch. looking at fcpeuro and ecstuning, im not able to find one for my car, what i was able to find is “Automatic Transmission Switch”.

Here is the part on ecstuning;
https://www.ecstuning.com/b-genuine-...h/24357581602/

The neutral/safety switch tells the DME if the transmission is in park or neutral, and based on this DME would allow engine to start or not. This is to prevent engine to start when transmission is in drive and car taking off uncontrolled. This is in addition to the requirement that the brake pedal is depressed when engine is being started. On a manual transmission car clutch switch is used for same purpose, engine doesn't start unless clutch is fully depressed.

I have a manual transmission E90, so had to look some what auto 328XI works. It is using a bowden cable that goes from the shifter to the transmission for selecting gears. So it is not "by wire" selection. But it doesn't have a traditional neutral/safety switch that is outside of the transmission where the gear selector is. Instead it is inside transmission and that seems to be the part you linked. Because it is inside the transmission, the information this switch has can only go to the DME (or the CAS module) via the mechatronic connector on the transmission. The switch looks like using hall sensors, not a mechanical contact switches. Hall sensor is less likely to wear out and fail compared to contact switches.

What I am arriving at, before you dish out hundreds of dollars on replacement for this switch component, it is better you get some diagnostics/troubleshooting done. Because it is very possible that the switch is working but there is something wrong with the electrical wiring from the transmission to the CAS. Or even maybe the transmission electronics is faulty. You have some bus errors, so more indication of electrical wiring or something similar going on.

The first thing to check looks like verifying electrical connection for park/neutral from transmission to the CAS is good.

Looking at TIS on the link, the wire that carries neutral/park information is called P/N:

https://www.newtis.info/tisv2/a/en/e...system/r14Nexa

In that link look for "automatic transmission" "P/N", which shows that from A7000a (transmission module) at connector X8500 pin 10, P/N wire comes out then goes to junction X6031 (which is inside box under the hood where the DME is also located) and from there goes to CAS connector X13376 pin 41. This probably has bus signal, so not on off, since it needs to tell both park and neutral switch selection. Checking no discontinuity or shorts to ground or other wires along that whole path should be done. Checking the signal form on that at the CAS end while changing gear would be another thing to check.

Another thing, maybe the Bowden cable and the mechanism that selects the gears at the transmission needs readjusting?

Also note TIS is showing two kinds of diagrams for the transmission module and its connector (mechatronics connector). In one of them the P/N is on pin 10, on the other it is pin 3. Both in both cases it is violet wire.

These two says "Applies to: gs19, gs1912, gs19a, gs19b, gs19d":

https://www.newtis.info/tisv2/a/en/e...ntrol/CjoZXUDV

https://www.newtis.info/tisv2/a/en/e...rol/1VnZ7QvVFf

These two otherwise:

https://www.newtis.info/tisv2/a/en/e...rol/1VnXlGCoPW

https://www.newtis.info/tisv2/a/en/e...rol/1VnZ6wejNS

One has pin 10 as P/N, the other pin 3. In both cases it is violet wire on the transmission side.

Transmission module electrical entry page:
https://www.newtis.info/tisv2/a/en/e...ssion-control/


Good luck!

[Bavarian Tech]

Have you tried to move the gear selector using the emergency release under the leather boot, for a first step. Then checking for results

[mastarron]

Originally Posted by matteblue3er

This right here is most likely preventing you from starting

Hard to say if its the shifter assembly but I have an auto gear shift assembly if you want it. $50 shipped or if you want to pick up, I'm in North NJ. The wiring harness was repaired but I pulled it from my car when I did a 6MT swap and it was working with no issues.

Hey matteblue3er,

Im no longer in the states, so having it shipped to Kosovo, would cost a couple of hundred at least. We were able to source one locally, but that alone did not fix the issue.

[mastarron]

Originally Posted by Bavarian Tech

Have you tried to move the gear selector using the emergency release under the leather boot, for a first step. Then checking for results

Once the car made contact I was able to move the gear selector between P, R, N, D and D/S, but it was not recognizing P and N.

[mastarron]

Originally Posted by PhaseP

The neutral/safety switch tells the DME if the transmission is in park or neutral, and based on this DME would allow engine to start or not. This is to prevent engine to start when transmission is in drive and car taking off uncontrolled. This is in addition to the requirement that the brake pedal is depressed when engine is being started. On a manual transmission car clutch switch is used for same purpose, engine doesn't start unless clutch is fully depressed.

I have a manual transmission E90, so had to look some what auto 328XI works. It is using a bowden cable that goes from the shifter to the transmission for selecting gears. So it is not "by wire" selection. But it doesn't have a traditional neutral/safety switch that is outside of the transmission where the gear selector is. Instead it is inside transmission and that seems to be the part you linked. Because it is inside the transmission, the information this switch has can only go to the DME (or the CAS module) via the mechatronic connector on the transmission. The switch looks like using hall sensors, not a mechanical contact switches. Hall sensor is less likely to wear out and fail compared to contact switches.

What I am arriving at, before you dish out hundreds of dollars on replacement for this switch component, it is better you get some diagnostics/troubleshooting done. Because it is very possible that the switch is working but there is something wrong with the electrical wiring from the transmission to the CAS. Or even maybe the transmission electronics is faulty. You have some bus errors, so more indication of electrical wiring or something similar going on.

The first thing to check looks like verifying electrical connection for park/neutral from transmission to the CAS is good.

Looking at TIS on the link, the wire that carries neutral/park information is called P/N:

https://www.newtis.info/tisv2/a/en/e...system/r14Nexa

In that link look for "automatic transmission" "P/N", which shows that from A7000a (transmission module) at connector X8500 pin 10, P/N wire comes out then goes to junction X6031 (which is inside box under the hood where the DME is also located) and from there goes to CAS connector X13376 pin 41. This probably has bus signal, so not on off, since it needs to tell both park and neutral switch selection. Checking no discontinuity or shorts to ground or other wires along that whole path should be done. Checking the signal form on that at the CAS end while changing gear would be another thing to check.

Another thing, maybe the Bowden cable and the mechanism that selects the gears at the transmission needs readjusting?

Also note TIS is showing two kinds of diagrams for the transmission module and its connector (mechatronics connector). In one of them the P/N is on pin 10, on the other it is pin 3. Both in both cases it is violet wire.

These two says "Applies to: gs19, gs1912, gs19a, gs19b, gs19d":

https://www.newtis.info/tisv2/a/en/e...ntrol/CjoZXUDV

https://www.newtis.info/tisv2/a/en/e...rol/1VnZ7QvVFf

These two otherwise:

https://www.newtis.info/tisv2/a/en/e...rol/1VnXlGCoPW

https://www.newtis.info/tisv2/a/en/e...rol/1VnZ6wejNS

One has pin 10 as P/N, the other pin 3. In both cases it is violet wire on the transmission side.

Transmission module electrical entry page:
https://www.newtis.info/tisv2/a/en/e...ssion-control/


Good luck!

PhaseP,

Thank you so much for the long and informative really! Really appreciate it!

According to the mechanic who I spoke to on the phone, he replaced the automatic gear shifter(which also has the bowden cable), and the mechatronic plate. He stated that the car is now recognizing P+N, but needs to code the new parts to the key fob? Does that make any sense to you? Maybe he also swapped the ECU?

Unfortunately the mechanics native language is not English so it is tough to understand, but according to him all of these used parts from another 328xi and labor will be 580 euros. If that fixes the problem Ill actually be quite happy. But I will read the codes with my carly scanner+app and report back for an update!

[PhaseP]

probably changed the transmission ecu (mechatronics plate?) and that needs recoding, just guessing.

[mastarron]

Originally Posted by PhaseP

probably changed the transmission ecu (mechatronics plate?) and that needs recoding, just guessing.

The automatic shifter and transmission mechatronics plate were changed, and the car is working great again!

Thanks for your input all!