I think everyone has speculated, but perhaps never had proof of built-in obsolescence... perhaps I may have.

After speaking with more people, including a BMW dealer technician, there is only one Gateway Module in the E64. There are three variants of the 93F9 code, but with the descriptor, the only part in the vehicle it could be was the gateway module (located under the glove box, covered by four screws on the passenger footwell kick plate --- very easy to access). The part is 65776960384, superceded by 65776975688. At the dealership, this part was C$1,660, plus labour (C$200/hr) and programming plus a C$500 core charge.

After watching LM Auto Repairs (Youtube), I decided to do more research on the video's claim ---- that the code comes from the large capacitors in the gateway module. After researching, and in large intent, trying to find the exact capacitors to purchase, I learned these capacitors come in 2,000 or 3,000 hours varieties. Thinking that was odd, it did some quick math.

I have 158,000 kms on the car. If I presume my average speed during that distance was 75 kmh (city 50 kmh / highway 100 kmh), then the vehicle has been driven (not operated) for approximately 2,100 hours. Interesting that the 93F9 code popped in and around 2,000 hours ---- perhaps the threshold life of the capacitor in the gateway module?

I found the exact capacitors at Mouser Electronics --- Rubycon 63MXG8200MEFCSN35X35 for C$10.93. Plus C$8 shipping, I purchased two (need two) for C$29.86. After disconnecting the battery, I pulled the gateway module and began to desolder the capacitors. I was largely unsuccessful using an 80W soldering iron and solder wick. I could get through the conformal coating (epoxy I believe) and remove the solder around the base of the pins, but could not free the capacitor. I took the board to a PCB manufacturer (I am sure any electronic parts business would be the same) to do the job. They told me the board has a full copper base, so it would be impossible to desolder using only an iron. They used hot air to heat the board, then focused on the pins to remove the capacitors --- it worked but the conformal coating is a little discoloured. They advise it will not effect the board. New capacitors were soldered in place and now the code is gone.

Avoided a multi-thousand dollar bill for C$30.

 

Hello..my name is Aaron I was looking at your problem that you were having with your BMW 645ci e64.. I have the same car and now my airbag light has come on..Sir is there anyway that I can get in touch with you on this matter of getting my problem solved.. I’m in Richmond Va. my e-mail is aaron12_@yahoo.com.. I would appreciate your reply..thank you

 

I am not exactly sure what the Autel unit will allow you to do, but it is a good diagnostic tool. I have one of the older ones my self. ISTA would be the preferred diagnostic software to look at all of the modules at one time. The safety module have ties to quite a few modules, so any safety module could trigger the fault. The 1st thing I am going to ask, what is the battery voltage with the engine off, & the ignition on? Anything less than 12 volts on thi battery voltage can trigger the code. If the battery is suspect, I would start there 1st. Below is the wiring schematic if you do not have it? I would delete every safety module separately one by on, then the SGM fault might clear. This can be done with ISTA, I am not sure if the AUTEL will have full access to the safety modules?

The DSC, SGM, SFZ, & both safety door modules can cause a code in the SGM module. Can you read the ECU & its functions with the SGM module. If the ECU can be read, it is most likely another module causing the code. I need to change my SZL module on my 645, but I have not had time to do it. The airbag light is trigged for a fault in this module on my car. I suspect that my steering angle sensor is the culprit. Chasing electrical problems on our cars can drive you crazy!

 

Hi Herb,

I like to try to fix things and be self-sufficient with my vehicles and found I needed a diagnostic tool. I cannot justify the professional model ones for what I do so thought I hit a good middle ground with the Autel. I am not familiar with the ISTA other than I believe it's software loaded on a laptop. Is this a pricey software? If I get there, where can I purchase it? I imagine there is a USB dongle for connection to the car.

Thanks Herb

 

The software is out there on the net, & the cable runs around 15.00 to 20.00. It is a pretty big download, but well worth the trouble. There are packages on Ebay with the cable for around 100.00, just find a good seller.

 

Hello: I am having the same problem with my 2005 bmw 645ci..my airbag light is on and I can’t turn it off…there was a time that I could turn it off and a few weeks later it would comes back on…now it stays on..is there any way that you could e-mail me so I can get some help on this matter this car is driving me crazy.. my e-mail is aaron12_el@yahoo.com I would greatly appreciate it..hope to speak with you soon…Thanks!

 

Autel makes good diagnostic tools, & will work well depending on the different model. If you got one that can read the modules on the car, it will serve you well. Remember that any module replacement will require programming, they are not plug & play.

Good find on the repair, post the part number info, & we can put it in the DIY section. IF you would like to do a DIY on this, that would be great for future members.

 

Exactly what airbag fault are you having? Have you done any coding to the Kombi module recently, or have you been have low voltage on the battery?