Value of resistor to fake out the airbag removal

My car is looking for about 3 Ohms based on the go/nogo criteria in the airbag firmware.

 

https://www.ferrarichat.com/forum/threads/whats-needed-to-bypass-airbag-light-when-replacing-steering-wheel-with-non-airbag-wheel.647759/#post-148092799

 

How are you going to reset the airbag light? Aren't they latched in the ECU?

 

I used a 3.3 ohm resistor for the passenger side airbag. This kit was nice since it had all sorts of resistors in case I ever need one in the future. https://www.amazon.com/gp/product/B08FHPJ5G8/

For the drivers side, I bought this kit from eBay. Came with the wheel, horn button, Hill Engineering adapter and the resistor. They don't specify what the resistance rating is, but it worked. https://www.ebay.com/itm/152730694664

 

Ah.. I misunderstood your message...

 

3.3 ohms seems to be the answer.

F355 Aftermarket Steering Wheel

 

At what percentage tolerance of the resistor?

 

I can't imagine it would be too critical. Even at 10% tolerance (silver band), that's only 1/3rd of an ohm. At least one person has used a 4.7 ohm resistor with success.

 

Remove the bulb. No impact on ecu or other. Have a write up on this when I did the steering wheel swap.

 

Isn’t it better to use a resistor to preserve the option of swapping back to the OEM wheel prior to a sale? I don’t plan on selling anytime soon and I’d hope a buyer would prefer the Momo wheel but I like the optionality.

 

2.7 ohm 1/2 watt is what I used and worked great.


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I was not comfortable using any resistors with the concern of shorting something out. If u sell the car, all u need is put the bulb back and reinstall your airbag wheel. Totally reversible. Also I was concerned of triggering the passenger unit.

 

As I understand, anytime the car is energized without detecting an airbag the system will display an airbag error that can only be disabled with Ferrari SD1 tools - aka a trip to the dealer.

Plugging in a resistor, using some electrical tape to prevent a short is about as easy as it gets. Far simpler than paying the dealer to reset airbag lights, IMO.

Also, I disabled the passenger airbag at the same time so my kid can ride safely. It’s even easier than the steering wheel airbag with the wires easily accessible under the dash.

355 AIR BAG LIGHT ISSUE

 

If you pull the bulb, you will also need to reset the system after reinstalling the airbag. As Ivan say, you'll need an SD tool. With the resistor (and the battery turned off during installation), you won't need the tool.

Interesting point. I don't have a 355 wiring diagram for the airbag system, but the later ones are probably similar to the Ferrari 360 system. There is separate wiring for each airbag (and seatbelt pretensioners on the 360), but I don't know how isolated the circuits are inside the Airbag ECU. Anyway, the act of removing and installing airbag connectors is probably far more risky than attaching resistors.

 

Google!

 

Mine is 3.3. It is too easy not to do it. Image Unavailable, Please Login Image Unavailable, Please Login

 

You guys have considered selling your cars and returning them to stock?

Thought never crossed my mind

 

I would Never sell……what other has the 288 GTO or F40 lineage for fraction of the money ….oh and that screams at you after 5000 rpm ….nothing else.

 

Seeing the mentions of my earlier posts on the resistance value to satisfy the TRW module when removing the steering wheel airbag, I decided to measure the airbag. First, the only reason I used a 4.7 ohm resistor is that it was the closest value that I had on hand at the time. While the 4.7 ohm did the trick, (a fuse is optional, but can’t hurt), best to go with a lower value resistor, as most suggest, 3.3 ohm. So, I went to my closet to bring my steering wheel for the measurement photo. I hurt my back lifting the thing, one heavy steering wheel. Results in the photo, 3.0 ohm…

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I have my 355 at my mechanic for an annual service and a few other things. One of them is to install the non airbag 355 steering wheel I recently purchased. When he did it and reconnected the battery, he got two codes, neither of them cleared with his SD-1 tool he has, so I had him unplug the airbag ecu all together. Wasn’t ideal, but he’s thinking I’d need to have it rebuilt and didn’t want that cost.

Anyone have similar issues?


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