Engine Cut Out on Highway - Need Help Diagnosing - multiple DME codes

[schnell944]

Hi, all. My wife was driving our '03 540it on the highway yesterday when the engine abruptly cut out and the trans failsafe message came up. She pulled over, put it in park and was able to start it again. This happened a couple more times -engine cutting out, power steering loss -- as she got it back to our house. Once home, I pulled the codes on my Foxwell NT510 and found the following:

67: DME: Function, monitoring control unit
73: DME: Signal, hot-film air-mass flow sensor
75: DME: Signal, throttle potentiometer
76: DME: Signal, throttle potentiometer 1
77: DME: Signal, throttle potentiometer 2
83: DME: Function, throttle actuator jammed
84: DME: Activation, throttle actuator
94: DME: EWS 3.3 interface DME-EWS
76: DSC: DME/DDE does not fulfil torque request

After clearing all the codes, only following two codes came back immediately:
83: DME: Function, throttle actuator jammed
84: DME: Activation, throttle actuator

I replaced the throttle body with a genuine BMW unit about 7 years ago, and I checked to see if the DME/EWS box was damp, but it was dry. Throttle body wires appear undamaged and dry, as well. MAF sensor is not all that old either.

Appreciate any thoughts on how to continue running this down, and if there are any likely suspects, given folks' experience. I obviously want to make sure this never happens again. Thank you!

[scottieducati]

Only time I had a similar thing happen it was the ignition switch. They can cause all sorts of wonkiness.


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[JimLev]

With only the 2 codes for the throttle still there I’d check to see if the throttle is really jammed.

[schnell944]

Ah yes! Forgot to mention, the ignition switch is also relatively new (5 years-ish, I think). I had trans failsafe errors at the time the switch went, but it was accompanied by the usual lighting gremlins and not these DME errors. That's not to say it couldn't be defective again though.

Jim - silly question, perhaps, but how can I check if it's really jammed? I don't think you can move it freely when the car is off, right? The throttle should be moving to some degree at least, since it was able to be driven home, and I can rev it in park.

[effduration]

Yeah we need to fix this....If this happened to my wife, I would never hear the end of it...

[Frankie]

Your throttle's electrical plug is fouled.

A nearly identical event happened to me. See my post in the E38 forum. You said you checked the wires, but your focus needs to be on the black connector plug. I replaced the entire connector on my E39 M52TU.

[MtnGn]

Your throttle's electrical plug is fouled.

A nearly identical event happened to me. See my post in the E38 forum. You said you checked the wires, but your focus needs to be on the black connector plug. I replaced the entire connector on my E39 M52TU.

Holy cats, that's a complex diagnostic problem. Nice work.

I have the preface-lift M62 with the 85-88 degree thermostat; in that DIY for this car, you pull that thermostat plug and leave it unplugged. The CEL does not come on. Run's well, just cooler as far as I can tell. Maybe there is a loss of mileage...? Regardless, aint no wicking going on.

[schnell944]

Your throttle's electrical plug is fouled.

A nearly identical event happened to me. See my post in the E38 forum. You said you checked the wires, but your focus needs to be on the black connector plug. I replaced the entire connector on my E39 M52TU.

Thank you, Frankie. That sounds plausible and similar to my situation. I'll start with cleaning the throttle connector and wrapping it for now. No wicking from the thermostat plug that I can see right now.

Yeah we need to fix this....If this happened to my wife, I would never hear the end of it...

You are very right about this one! Unfortunately, I gave her the E32 to drive in the meantime, and that had a stalling event, as well. She is researching minivans as we speak...

[effduration]

[QUOTE=schnell944;30885359]Thank you, Frankie. That sounds plausible and similar to my situation. I'll start with cleaning the throttle connector and wrapping it for now. No wicking from the thermostat plug that I can see right now.

Clean the connector with DeOxit or Stabilant-22

[schnell944]

Just cleared the codes and ran the car for a bit before cleaning the connector, and the codes did not come back/it ran fine. Perhaps some water got in there and evaporated since the incident? Trouble now is I won't be able to definitively know that I've fixed it since the codes are no longer persistent.

For the locking collar on the connector, I'm having trouble seeing how to disconnect it and am cautious not to break it. Any tips or instructions on separating the collar from the rest of the connector. Thanks!

[schnell944]

A word of caution that maybe only I was aware of -- dont get the DeOxit contact cleaner on the rubber piece of the connector. It caused the rubber to expand, making it quite difficult to get the connector back on. It's back on but a plastic piece did break. Unfortunate that I also sprayed my MAF connector while I was in there...cant get it back on for the same reason. Can anyone help with how to take the locking collar of the MAF connector?

image0 - Copy (7).jpegimage1 - Copy (7).jpeg

[schnell944]

Update: thought I fixed it, and the car ran fine for over a week, then it stalled again today. Wife noted it ran "odd" when she started it up after work, then is stalled while stopped, started up fine, then cut out and started again while driving, throwing a limp mode message. I ran the codes and this is what came back:

- DME: signal, throttle potentiometer
- DME: Signal throttle potentiometer
- DME: Function, throttle actuator
- DME: Spring check, throttle actuator

We've seen the first three earlier, but the spring check is a new code. After clearing the codes, the "DME: Function, throttle actuator" code came back immediately before starting the car. Cleared it again and drove the car, and after a couple mile ride, no issues or codes returned.

As I noted above, the throttle body was replaced (checking records, it was replaced two years ago) with a new, genuine BMW item. I just noticed its manufactured by VDO and thought I heard about VDO throttle body issues?

Anyway, I'm out of ideas beyond throwing parts at the issue with fingers crossed. Any thoughts on what this is most likely pointing to are appreciated (especially given the new "spring check" code) - throttle body vs accelerator module or something else? Thank you!

**adding that using my scan tool I found that the absolute throttle position rests at between 2 and 2.4%. Unsure if that is indicative of anything though.

[scubajim20]

Maybe buy a used throttle body at the junk yard or ebay to see if it helps. Trying to keep the costs down.

[rlordjr]

First replace the connector that goes into the throttle body. Requires some wire cutting and soldering but has fixed this issue for many people including me. I chased the same symptoms and tried new TB, accelerator pedal, and probably more.

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[schnell944]

Did you keep the same wire terminals and just replace the connector or trim back and replace everything? How far did you trim back and replace the wires? Do you have a recommendation for a pin removal tool that will work with that connector? Did you have similar error codes? last question is if you have the part number for the terminals handy. The socket housing is 61138383300 but I can't for the life of me figure out which terminal is the right one. Thank you!

First replace the connector that goes into the throttle body. Requires some wire cutting and soldering but has fixed this issue for many people including me. I chased the same symptoms and tried new TB, accelerator pedal, and probably more.

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Have folks ever had issues that were fixed by a new accelerator module? Do similar codes show up if it's an issue? I have the later e pedal which apparently is prone to potentiometer issues.

[Frankie]

You need to replace the connector AND the wires -- the whole thing. Splice back about 6 inches. Cover with heat wrap. Wire pins are 61130005197.

[rlordjr]

Here's my order of pins and connector. There are better pins which have grommets on them but I don't have that number. Just search for bushing contact

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[schnell944]

Thank you! Ordered.

[JimLev]

When I replaced the TB connector and pins I bought this P/N for the pins, they came with 18” of wire attached too the pins.
https://www.realoem.com/bmw/enUS/sho...16#61130006665

image.jpg

[rlordjr]

Yep those are the better ones with the grommets.

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[SW530]

I'm currently dealing with what sounds like the same issue, same connector, same crusty wires, same symptoms. A few things I discovered that might apply to your situation is that the throttle body plug, once you plugged it in, looked plugged in. But it wasn't. You push it all the way in as hard as you can, then it springs out a bit, and you think it's right. But pull on the connector a bit and it comes right out. When the plug is in this position the car surges and runs terrible. If you use a screwdriver to bridge the rear of the plug and pull it back until you hear it "click" in, then it stays and it runs properly. I would guess this plug being properly "clicked" in is key to it running right, and when it manages to click itself out.. that we have issues. The solution of course is to replace the plug, wires/connectors, and to bring them back 6-9" and replace that much wire. Looking at the replacement plug it appears to be made of a different material than the original. In my case the previous owner had done something to the plug and them wrapped it up in E-tape. I'll dissect it once I cut it out and see exactly what they did. But if the skill with which they wielded the E-tape is any clue it could be anything. I can't complain, this is the first thing on my car in the few years I've owned it which has affected how the car ran.

[xjokerz]

Wow, seems like a pain. Does this issue come up consistently in the V8 models or can it also affect the 6's?

[Frankie]

...can it also affect the 6's?

As they age, all BMW's with electronic connections at the throttle are vulnerable (including electro-mechanical and fully electronic throttles). This includes both I6 and V8 engines.

[effduration]

Wow, seems like a pain. Does this issue come up consistently in the V8 models or can it also affect the 6's?

Its very common on the 6 cyl M52TU engine cars (3,5,Z series), and less common on the 6 cyl M54 engines.

The two engines use different throttle bodies and connectors, and the 10-pin TU connector is often a source of problems.

[schnel944]

Well, this issue has cropped up again a bit over a month later, even after cleaning the connection to the throttle body and after diagnosing what looked like a communication issue with the accelerator module. I recorded the following codes after my wife said it ran a bit rough:
- DME; spring check, throttle actuator; DME: DMTL minor leak
I cleared the codes then took it for a drive. I then got a trans prog failsafe message and the DSC OFF light came on. Back home, checked the codes and pulled the following:
- DME: signal, throttle potentiometer; DME: signal, throttle potentiometer 2; and DSC: DME/DDE does not fulfil torque request.
Not sure what the heck is going on. Have a spare throttle body I'll throw in but other ideas welcome.