DRIVETRAIN MALFUNCTION/DRIVE MODERATELY Warning - UPDATE

[NorthCountryGuy]

Guys,

Just got off highway (cruise control 72mph). Stopped at light for a few seconds and then a bucking. Above Warning on panel. Made through light double pedaling, but had to stop at next light. Then stall. Would not restart. Starter cranked but would not idle. I’m in right lane of a busy boulevard so triangles out. 10mins later restarts and drives home without issue. Plugged in and no OBD or BMW DTC’s.

First thing to my mind is battery ground and will check shortly (had to cut the grass before the rain).

Your thoughts and/or experiences with the similar...

Thanks in Advance
Craig

[hugo_nz]

Ignition coils and/or injectors but most likely the coils. Pull the codes for the cylinders misfiring, swap the coils and and if the problem follows the coils you have your answer.

[NorthCountryGuy]

Originally Posted by hugo_nz

Ignition coils and/or injectors but most likely the coils. Pull the codes for the cylinders misfiring, swap the coils and and if the problem follows the coils you have your answer.

Unless I scan while the malfunction occurs, I can’t capture it. Also it is not stored as a legacy.
As the car is relatively new to me, new coils and plugs is a thing to be done. Bosch material ordered today.
Thanks again.

[hugo_nz]

Originally Posted by NorthCountryGuy

Unless I scan while the malfunction occurs, I can’t capture it. Also it is not stored as a legacy.
As the car is relatively new to me, new coils and plugs is a thing to be done. Bosch material ordered today.
Thanks again.

It does store error codes. Shows as missfire or fuel supply cut off.

[NorthCountryGuy]

Since the event, I’ve put on the car about 100 miles without any event or loss of performance. Scanned and no OBD2 or BMW OEM Enhanced DTC’s stored or found live.

[NorthCountryGuy]

Got the same Drivetrain Malfunction Warning on my 750 Li. Went into safe mode as well. As it’s my Son’s primary vehicle, we serviced that first. My 650 will wait. Here’s the cause. After changing out all plugs & coils runs like silk with no warnings. Just thought I’d post to show a cause for such a Warning.

[ezmaass]

Thanks for the update! How many miles are on the car?

[DRock3d]

wow are those original plugs? I've heard these toast plugs in as little as 10k. That thing is missing ceramic and half the electrode.

[NorthCountryGuy]

Originally Posted by ezmaass

Thanks for the update! How many miles are on the car?

The 750Li has 93K

Originally Posted by DRock3d

wow are those original plugs? I've heard these toast plugs in as little as 10k. That thing is missing ceramic and half the electrode.

I imagine they were likely the originals.

[NorthCountryGuy]

The Prince is now ill.
After replacing plugs & coils the car ran as it should for a while. Drove about 10 miles, picked up a venti Pike, and was going to go for a cruise and monitor the car. Pulled out of Starbucks and the car started to lurch when at single digit speed and low rpm’s. Not a cylinder misfire shimmy, but was as if I was slamming on the brakes. My coffee in the cup holder even took a dive. I then pulled over out of traffic. Car would start then stall. Finally double pedaled to keep it running and after multiple attempts got it into drive and limped home.

Drivetrain Malfunction Warning
Some sort of Steering Warning
Some Transmission symbol warning
Chassis stabilization Warning

First thing I did was disassemble and check the coils/plugs.
Everything in place. Everything attached firmly.
Checked near everyplace I moved something to see if I violated some harness connection, but none that I could discern.

Plugged it into to my obd2 with BMW enhanced codes and nothing.

He’s going to have to go into the hospital for this. Will have to flatbed it there.
F#@king hassle.
What burns even worse is that I had just done one of my thought out, ‘clean’ tasks on the car.
Just thought I’d share.
Will update after reparation.

[NorthCountryGuy]

Went out and restarted the car. Started and idled smoothly. Took it down a quiet lane by me at about 20 mph and the bucking started again. Turnt around. Got into the garage and did get codes. Some were the result of power reduced operation. Two that stood out to me were 160xxx codes. These speak to faulty crankshaft sensor. Does make sense with the bucking. It feels like the engine starts and stops and starts rapidly.

Is a crankshaft sensor job something I can do, or does it require any type of computer coding beyond me and requires shopwork ?

Thanks in Advance
Craig

[NorthCountryGuy]

It looks very straightforward on newtis.com to replace this sensor on the transmission housing.
There must be more to it...
Anyone have any experience with it ?

[NorthCountryGuy]

The crankshaft sensor install was to easy so I was therefore expecting a complication.
So far, there was none.
It must do one cycle to get to the reference gap of the increment wheel of the crankshaft to orient to TDC of cylinder 1, and set itself.
Drove for some miles and so far all is well.

[NorthCountryGuy]

Nope. No good.
Some bucking started again. Drivetrain, Chassis Stabilisation, Transmission Temp warnings.
Got multiple codes for faulty Crankshaft sensor, implausible crankshaft rotation...
Codes also for transmission temp sensor. This is odd for engine wasn’t even really warmed up and was driving very gingerly on non populated roads for my test run after sensor change.
I now will give up and give to another to fix. Beyond me at this point.

[NorthCountryGuy]

Anyone ?
Any ideas on this malady ?
Very quiet here for a technical Forum.

[hugo_nz]

Your car is throwing a very diverse range of codes. Do you have access to BMW ISTA to do a proper diagnostic? I had the drivetrain and stabilisation codes come up while I was converting from CIC tot NBT iDrive, but that was due to the CAN2 wires popping out of the quadlock behind the iDrive computer.

The trans temp warning is an odd one. Your best bet would be to get the car hooked up to ISTA.

[NorthCountryGuy]

Originally Posted by hugo_nz

Your car is throwing a very diverse range of codes. Do you have access to BMW ISTA to do a proper diagnostic? I had the drivetrain and stabilisation codes come up while I was converting from CIC tot NBT iDrive, but that was due to the CAN2 wires popping out of the quadlock behind the iDrive computer.

The trans temp warning is an odd one. Your best bet would be to get the car hooked up to ISTA.

Hugo,
Thanks and agree.
I was hoping some of the Wise would chime in for I’m stumped. The OBD2 and BMW enhanced codes were the same, and like you said, all over the place. Some codes predictable sensing of Safe Mode conditions (low voltage/low pressure here and there).
I was just hoping to gain from the experience of the Wise a possible direction to pursue. Also would’ve help me read up on specifics so when I talk to my Guy I can speak precisely about matters. They already know I know cars, but I have found it is always good to position yourself so as not to be ‘spoken over’.

Thanks again

[NorthCountryGuy]

Car will go in after the weekend, but I had to settle a few things in my mind which was which code(s) were the cause and which were a consequence of the altered running of the car and/or various sensors.
First I measured the battery voltage - 12.4 V
When I went to measure the battery voltage via my Foxwell scanner, it would not give a value for it stated an IBS fault not allowing battery data to go to the DME controller and subsequently my scanner.
Car starts and idle clean and smooth. The only DTC that came up was a D35476/Intermittent. This is a torque crankshaft invalid signal. The description given for this code is as follows from a look up of BMW codes:

‘The control units exchange information via the bus.
An "interface error" (invalid signal) is stored when urgently required signals are only received in the form of a substitute value or as an "invalid signal".
The fault is logged when the partner control unit (=interface) transmits a substitute value or a value designated as invalid instead of the required information. In this case, a fault code should also be stored in the corresponding partner control unit.’

The BMW service plan for this fault is as follows:

‘Work through all stored faults of the partner control unit according to the test plan.
Especially faults that affect the vicinity of the partner control unit (e.g. connected sensor system).
These types of faults are consequential faults.
If there are no further test modules in the test plan then no further repair measures are required.’

Additional service note:

‘The fault is not in the control unit that records the interface fault. For this reason the control unit must not be replaced.’

This narrows the hunting field down considerably. At least I can speak with some knowledge of the situation and not be rolled over by allowing/paying for time on a gigantic hunt of things not needed.

[NorthCountryGuy]

The Guys at Cantech Motor Works in North Syracuse did a first rate job.
The vehicle’s malfunction and codes were speaking to a signal malfunction and not an actual hardware malfunction.
I’m pretty good with auto electrics, but I couldn’t solve it.
Even having ISTA, Mike (the SA) said it was a difficult case.
It ended up being a broken wire in the BUS of the crankshaft sensor circuit.
What I did find was a new found respect for the tenacity of the the tech of record in this case.
Case closed.

[NorthCountryGuy]

I missed the Prince and my decompression drives with him.
It was a 70 mile saunter home from Cantech on 81 North, and the feeling returned immediately.

[Yorkie36]

Glad you got it all sorted in the end 👍

[NorthCountryGuy]

Originally Posted by Yorkie36

Glad you got it all sorted in the end 👍

Kindly,
Thank you.