[JasperBMW]

Lately I've had a few issues pop up in my E91 from 2005/2006 with a N46 engine. For a while now, when parked in front of a traffic light, it has a rough idle, seemingly misfiring. It was just a nudge but it was definitely noticeable.

Then last month, just before arriving home on a cold snowy day, my dashboard lights decided to throw a party and my car went into limp mode. After seeing a lot of different warning signs flash by, I immediately pulled over and cut the engine. The main one sticking was a red transmission fault icon. After some googling, I waited it out and tried restarting the engine and was able to drive back home alright.

Because some things seemed to point to a faulty battery, and knowing mine is failing, I got it replaced. It felt like the idle in front of traffic lights was really rough now, shaking the entire car. Yet I was able to make 2 small trips without any further issues. Until the lights came back on the 3rd trip. Parked close to home as soon as possible and ordered a OBD2 dongle to read my codes.

I fired the car up just now and when driving in reverse, and slowly forward, the shaking was mad. Surprisingly I'm not seeing any injector codes or anything. What I'm seeing is:

12 Engine electronics
2A83: CDKENWS - Camshaft Control - Inlet
2B5C: CDKN - Crankshaft encoder

18 Transmission control
51A7: Signal (engine speed) from the engine control faulty

29 Dynamic stability controlMK60
5E1A: 5E1A - CAN DME / DDE signal error.

40 Car Access System
A0B4: Fehler_Motorstart_Anlasserbetrieb

56 Function centre, roof
A670: Error fitting sensor 0xA670

56 Function centre, roof
A670: Error fitting sensor 0xA670

72 Driver's side footwell module
9CBD: Communication with StepperMotorBox left disturbed
9CBE: Communication with StepperMotorBox right disturbed

29 Dynamic stability controlMK60
5E1A: 5E1A - CAN DME / DDE signal error

Does anyone with more knowledge have any clue or indication as to what the issue could be? Crankshaft sensor? Camshaft itself? Would like to have some sort of indication before bringing it in for a full service.

Edit; could it be the ground strap causing all this? Will get some jumper cables tomrrow to test if it makes any difference. Don't have a jack so I cant look at the actual strap

[e91Owner]

It sounds from your other thread that you are taking this to a specialist. However, the crankshaft position sensor is the likely culprit based on the codes you provided. In the US, they are cheap and easy to obtain from any auto parts store, but as with the N52, creating access is the lengthy part of the repair.

If you do decide to replace it yourself, you will need parts 3/4/5 on the diagram below:

https://www.realoem.com/bmw/enUS/sho...73#13627548994

And here is one person’s tutorial on how to access it to replace it:

[dxrkk335]

This is very intriguing to know I was the only one with this issue. Not saying this to scare ya but when I had my 06 325i this happened similarly but my transmission was cooked. But seemingly enough probably some sensors. How many miles are on it if you don’t mind me asking?

[JasperBMW]

Originally Posted by e91Owner

It sounds from your other thread that you are taking this to a specialist. However, the crankshaft position sensor is the likely culprit based on the codes you provided. In the US, they are cheap and easy to obtain from any auto parts store, but as with the N52, creating access is the lengthy part of the repair.

If you do decide to replace it yourself, you will need parts 3/4/5 on the diagram below:

https://www.realoem.com/bmw/enUS/sho...73#13627548994

And here is one person’s tutorial on how to access it to replace it:

Thank you, that was an interesting watch! I'd prefer doing my own repairs where possible but depending on the severity of work required and whether I need to jack it up or not. As I currently have to do any work in my public parking spot on the street. (Luckily getting a sort of carport soon!).

Today I tried to troubleshoot the ground strap by routing some jumper cables from a screw on the engine to a screw on the chassis. I cleared the error codes and ran the engine. Drove back and forward a bit in my parking spot. The issue definitely felt less noticeable! Although there were still some rough spots when driving very slow. I repeated this for a while and no error codes showed up this time..

So I do wonder if it is the ground strap after all. As far as I know, that one is pretty hard to replace without jacking it up so I need to contact a close by garage tomorrow.

Originally Posted by dxrkk335

This is very intriguing to know I was the only one with this issue. Not saying this to scare ya but when I had my 06 325i this happened similarly but my transmission was cooked. But seemingly enough probably some sensors. How many miles are on it if you don’t mind me asking?

Not entirely sure, this car was bought used for a company in 2022 and just had the entire engine and transmission replaced with fairly new ones. There's no notation of the miles at the time of the sale in 2022. It was not used that much and I took ownership late 2024, and drove Maybe 20-30k miles. But because of the circumstances I have no clue as to the mileage on the current transmission..

[e91Owner]

It’s unlikely the ground strap. It wouldn’t affect the codes you are getting. A bad ground strap would manifest in the starting first.

Also, FWIW, you would want to ground the block to the negative stub in the engine bay. It should be on the other side of your coolant reservoir protruding from the fender.

To assess any grounding problems, simply test the voltage between the +/- terminals and the + terminal and the block and compare the two readings.

[JasperBMW]

Originally Posted by e91Owner

It’s unlikely the ground strap. It wouldn’t affect the codes you are getting. A bad ground strap would manifest in the starting first.

Also, FWIW, you would want to ground the block to the negative stub in the engine bay. It should be on the other side of your coolant reservoir protruding from the fender.

To assess any grounding problems, simply test the voltage between the +/- terminals and the + terminal and the block and compare the two readings.

Cheers thanks for the tips I'll check it out while I wait for my appointment to get it properly checked out.

[JasperBMW]

The garage quite quickly diagnosed it as the crankshaft position sensor but it took quite a long while for them to order a replacement part and get it in due to illnesses. We were able to pick the car back up on Wednesday and while they said the previous maintenance looked sloppy, the sensor was replaced and that should solve the issue.

Sadly, today my gf drove a 100km roundtrip and again noticed the shaking and idle rev

[JasperBMW]

I just had a short drive myself, noticed the idle rev was indeed still there but it was way less violent than it used to be. A gentle nudge instead of a violent shudder. Nevertheless, not ideal.

Scanned the engine codes and got:

2 errors

2D32: CDKDPSRPL - plausibility pressure sensor intake manifold 2A83: CDKENWS - Camshaft Control - Inlet

So, I decided to look under the hood and boy, it is a mess down there. Lots of old oil and dirt build-up. I was looking into switching the inlet and outlet VANOS but this needs proper cleaning first.





I've also noticed that on the right side of the engine, there is a disconnected hose. Could anyone tell me what that hose is for? Not sure if the mechanics left it disconnected for a reason or if it just wasnt secured properly.

[JasperBMW]

Connected the hose, drove around a bit. Quite some shudders and rescanned:

2A59: CDKDVFFS - VVT lead sensor
2A5B: CDKDVFRS - VVT Reference Sensor

Guess this means the ESS is fried and needs replacement quite soon? I've seen repeated messages of buying an OEM one, they're quite pricey at 350-400€ (especially compared to the aftermarket ESS) and at least the same price for labor costs.

Wonder if it's still worth the investment or if we should be looking for something new