S65/S85 throttle actuators - electrical failure SOLVED

[M3MPH1S]

Originally Posted by meyergru

https://www.ebay.com/itm/5PCS-HUFA76...-/192129331828

Oh duh! I always forget to check eBay.


Thank you sir!

[pbonsalb]

Thanks for the link. I had seen a set for about $75 a while ago advertised as a throttle actuator repair kit but was hesitant to invest that much more into what is likely a losing proposition. But at $15, I’ll give it a try since I currently have 1 new actuator and 1 original with new gears. I also have 2 others that I put new gears in that don’t work, which sort of soured me on the repair concept - a pain to swap in and out repeatedly.

[M3MPH1S]

Originally Posted by pbonsalb

Thanks for the link. I had seen a set for about $75 a while ago advertised as a throttle actuator repair kit but was hesitant to invest that much more into what is likely a losing proposition. But at $15, I’ll give it a try since I currently have 1 new actuator and 1 original with new gears. I also have 2 others that I put new gears in that don’t work, which sort of soured me on the repair concept - a pain to swap in and out repeatedly.

Yeah that's my thoughts as well. I have had a bank 1 error code come up twice over the past 4 weeks while cruising down the interstate at a fixed speed (no acceleration). Pulling over and turning the car off and back on has cleared it with no issues so far, but I'm guessing it won't be much longer until I get the permanent error code like others. I was honestly ready to just drop $1,140 on a new pair and be done with it, but I saw FCP Euro had the gear repair kit on sale for $115 (https://www.fcpeuro.com/products/bmw...odometer-gears) vs the normal $225, so I figured it's worth a shot at least. You are definitely right about it being a pain to get in there. I'm really not even sure if I want to try replacing the FETs, but it will be nice to have them on hand as an option. However I feel like if I pop my TA's open and the FETs are showing burn marks I will just concede defeat. We shall see...

[drummer20]

Originally Posted by M3MPH1S

Reviving this thread to see if anyone has been able to find the FETs lately. All of the links in this thread as well as what I can find on Google are showing the part is discontinued and no longer being sold.

The replacment part is HUFA76429D3ST-F085 available at:
https://www.mouser.com/ProductDetail...-Semiconductor

The specs are identical.

I did notice that the new part is now:
AEC Q101 qualified and RoHS compliant which is probably the reason for the new part.

Note that replacing the FETS didn't help my problem and I was all in on DIYing this one. I also changed gears, FETs and even changed some other ICs to try and make it work. I finally bought two new TAs

[kanid]

Hi,

Thought I would share a discovery I made while replacing my throttle actuator gears with odometergears on my 08 M3 that could be the cause of the electrical failures of the FETs on the circuit board.

I noticed that the two electrical leads that connect the motor to the circuit board have a spot welded joint at the 90 degree bend coming out of the motor. In both of my actuators both joints were failing leading to a poor electrical connection. Just wiggling the connectors I was seeing a large resistance variation due to the spot welded connection.

One theory is that the spot welded joint is insufficient and failing due to thermal cycling or vibration. This could certainly wreak havoc with the power drivers for the motor causing premature failure.

My solution was to solder this connection with a large iron tip. They are solid now with no deviation. I see about 2.5 ohm with good connections.

Something to definitely check if you have your actuators apart.

-Kanid

[gazosnic]

@kanid - please report back if this resolved the issue for you

[douglee25]

Interesting info.

[Joel32488]

Hello guys, If anyone needs their throttle actuators refurbished you can send them to Easy Tech located in Miami, fl. PCB MOSFETS replacement and gears. Check out their Instagram feed for pictures and details. @easytechmiami.

[AR71]

Hi,
I had the same error message so I decided to do the dyi cleaning.
Unfortunately while finishing up, I managed to over tighten and break one of the shiny screws on top of the intake plenum. Can someone please advise what this screw does and whether it’s safe to start and drive the car?

[meyergru]

Those screws supposedly hold metal rods in place inside the plenum that are there to prevent resonation by connecting top and bottom to make it stiffer. You don't need to touch them in order to get the plenum off or on - nor should you.

Now that one rod is no longer connecting top and bottom, you may experience more drone from the plenum. I cannot say if parts may be loose enough to roll around and finally can get into one of the intakes, so you'd better check that.

[pbonsalb]

Those shiny nuts are part of interior supports between the top and bottom of the plenum. They don’t undo. I think the support is molded in place.

[AR71]

Thanks for the replies, I was afraid something might get lose and get in through the intakes. Seems all right.

[douglee25]

Nice!

Are you buying cores?

[gazosnic]

Originally Posted by abdul28

I’m excited to announce the first Throttle Actuator Rebuild service in North America. As we all know, throttle actuators on our cars are one of the few weak points. They are bound to fail! They have a major design flaw that BMW will never admit to. I’m sure I speak on behalf of majority of the M5 owners on this board when I say that the prices of new actuators are just outrageous.

After weeks of testing and research and successfully rebuilding more than 12 units for myself and my friends, I was convinced it was time to offer my services to my entire extended M family. I contacted many knowledgeable BMW master mechanics throughout my process. They were all crossing their fingers and were excited to see the results of my experiments.


Along this journey, I bumped into a great guy by the name of Jason from Rebuild UK. After many conversations, we came to a conclusion that I don’t have to reinvent the wheel. He is already providing this service for the last few years. But unfortunately, only 3-5 percent of his customers are from North America due to the ridiculous shipping costs that are associated with shipping to the UK from North America. According to him, it wasn't worth it for Americans or Canadians to send him faulty actuators to get refurbished due to the shipping costs, potential customs charges, and the intolerable wait period!


After many conversations, I have decided to launch M Power Motorsports as the North American Supplier for Rebuild UK. Same proven product minus the shipping costs, customs costs, and shipping time! Please take a look at my website and contact me through my website or this board. Thanks

Cost: $350.00 (Per Unit)
Shipping and Handling time:48-72 hours

Website: https://www.mpowermotorsports.org/
Phone Number: 7347304411

Aren’t the VDO ones from FCP 499 new w lifetime warranty? If so the price detail of $150 less for repair option doesn’t seem too compelling. Maybe I’m missing something though. Also it seems there is still a mystery on repairs working 100%.

[Kamen]

https://www.fcpeuro.com/products/bmw...SABEgJPF_D_BwE

[gazosnic]

Originally Posted by Kamen

https://www.fcpeuro.com/products/bmw...SABEgJPF_D_BwE

thanks - this is what I was referring to.

[are0lies]

Originally Posted by abdul28

I find something very interesting/suspicious. I got a few calls from representatives of some major BMW online part stores. They didn't appreciate me selling Actuators for the price I'm selling them. To say the very least. I told them, once they decide to lower the prices on the actuators, I will stop selling. Until then, we don't deserve to be taken advantage of.

Good on you for basically telling them to go f themselves. But I also hope that you are also having a decent return for your efforts. Thanks.

[Honda]

Originally Posted by abdul28

The replacement gears we use have a lifetime warranty and they are self-lubricating and designed to outlive the car. The plastics we use are second to none. Our replacement gears are better than the original equipment fitted in the cars. The OEM unit irrespective of where you buy it from will have the low-quality OEM gears that came with the car and will definitely wear out over time.

What I mean by 100% repairs working is our Rebuilt units work 100% of the time. And once we have remanufactured the circuit board and replaced the gears with superior materials, it will not need to be replaced again. However, if it ever does, it has an unlimited mile-lifetime warranty so we will replace it.

are you guaranteeing that the circuit board is repaired/refurbished as well? Most of the failures are NOT from the gears as many people think. Also has this been tested for failed ones and for how many miles?

[svinfinity]

Originally Posted by abdul28

I find something very interesting/suspicious. I got a few calls from representatives of some major BMW online part stores. They didn't appreciate me selling Actuators for the price I'm selling them. To say the very least. I told them, once they decide to lower the prices on the actuators, I will stop selling. Until then, we don't deserve to be taken advantage of.

Let me guess, ECS Tuning or Turner Motorsports?

[E92_TYLER]

You will be hearing from me shorty..

[nycplumber]

We would have to ship the TA to you to be rebuilt or we would simply order directly from you?

[pbonsalb]

This is a great deal. I tried fixing my own. Spent the money on new gears and the time to change them. Did not work. I must have installed and removed the actuators half a dozen times trying to test and swap them. I spent money and wasted time.

Often the faults are the electronics, although the gears may be worn as well. If you do all the research like I did, you will find reports of people changing the mosfets, which you can do if you want to buy them and are good at desoldering and soldering and don't think you will screw up other circuits on the board, but that did not fix things for most who spent all the time trying. The reports are very mixed. Probably if you are a real electronics guy with the right test equipment you could figure out the faults on the board.

Most of us are not in that category. I am a good DIYer, but this is probably beyond me and definitely would take more time than I want to put into the job. I ended up having to quickly order a new actuator last year and paid about $650 for it.

Recently, I got a second actuator from Abdul at M Power Motorsports. He knows what he is doing and is also working with Jason from Rebuild UK who has a business over there refurbishing the actuators. Seems like a great service he is offering. Much cheaper than a new one, and the new one has the same parts that failed in the original one.