Passenger Presence Sensor Bypass?

Tiny
JIM IN HAWI
  • MEMBER
  • 2017 CHEVROLET VOLT
  • 15,000 MILES
The dealership diagnosed this airbag sensor issue and determined a new seat sensor is required ($1200 + labor). We simply want to enable the airbag for the passenger seat full-time. Never children riding nor do we care if it goes off unoccupied. There's a bypass module from airbag 360 for the previous model range (up to 2015) and hoping there's a means to provide a similar bypass.
Monday, January 2nd, 2023 AT 4:05 PM

9 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 48,363 POSTS
I can't tell you how to bypass safety devices on your car but I can give you the wiring diagrams so you can see how the system works so you can go from there. Check out the images (below).
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Tuesday, January 3rd, 2023 AT 10:08 AM
Tiny
JIM IN HAWI
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Thanks for the diagram, as I suspected the PPS appears to be on the CAN/LAN (LO SPD GMLAN) as labeled in your diagram, so there's no bypassing a contact or other simple permissive. Are there any diagrams showing additional connection to the PPS? Somewhere, somehow this connects into a capacitance-based sensor that's incorporated into the seat, unless "said" sensing is built directly into the module? Appreciative of any other insights or direction.
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Tuesday, January 3rd, 2023 AT 10:51 AM
Tiny
KEN L
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Yes, the sensor is built into the module, here are the rest of the airbag wiring diagrams so you can see how the system works. Check out the images (Below). Please let us know what happens.
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Wednesday, January 4th, 2023 AT 7:33 PM
Tiny
JIM IN HAWI
  • MEMBER
  • 5 POSTS
Ken,

You say, "here are the rest of the diagrams", but no image/attachments that surface.

Thanks again in advance.
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Wednesday, January 4th, 2023 AT 8:49 PM
Tiny
KEN L
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My bad, I updated the post.
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Thursday, January 5th, 2023 AT 12:31 PM
Tiny
JIM IN HAWI
  • MEMBER
  • 5 POSTS
Thank you, Ken,

The diagrams are glorious, and should I need any point-to-point troubleshooting I am indeed ready with your diagrams.

Since the only means to spoof the Sensing and Diagnostic Module is to provide it with the proper CAN codes from the passenger-side PPS module, do you by chance have access to the specific CAN message frames that it requires?

I'm an embedded developer and it wouldn't take a lot to create a CAN-based node on this LAN. If you have these codes, I'd appreciate you providing them.

As an aside, I've sent multiple messages to the Airbag360 group (in Ireland) to no avail as I was hoping they could shed some light on the sensor hack. They have a module for the prior Volt model, so if the codes haven't changed across models, this could ultimately be a win... here's the link:

https://airbag360.com/chevrolet-volt-front-passenger-side-airbag-seat--occupancy-sensor--emulator-704-p.asp

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Thursday, January 5th, 2023 AT 1:10 PM
Tiny
KEN L
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I am sorry we don't have the codes you are asking for, but it sounds like you are on the right track. Use 2CarPros anytime, we are here to help. Please tell a friend.
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Thursday, January 5th, 2023 AT 1:18 PM
Tiny
TINYSOX
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Hey Jim in Hawi, did you ever build that override module you were talking about?

I have a 2013 Volt with the same problem and bought the airbag360 emulator you linked, but it doesn't work very well, and the person running that store is difficult to communicate with. I'm also interested in a DIY approach.
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Monday, July 3rd, 2023 AT 2:12 PM
Tiny
JIM IN HAWI
  • MEMBER
  • 5 POSTS
I was surprised to see a comment on this thread. Like you've experienced, the Airbag360 individual is difficult to engage, and in I've received one reply from him out of double-digit attempts. In this one reply he also admitted to CAN issues with the existing module, specifically with the emulator working only once, and failing thereafter (exactly your experience). He said they've stopped selling them for the time being.

I was hoping to at least get some idea as to which frames are relevant to the PPS sensor from him as at least a jump start, however, that was a dead end. Unfortunately, at this stage a hack feels like it might be a search for a needle in a haystack.

I just finished a CAN project node for my day job pursuits that is sending real time weight and recipe data to a self-loading agricultural commodity mixer. Knowing the specific frame data is the "secret sauce" to making this possible.

I'm also head-scratching the gm engineering decision that renders the airbag off in a PPS sensor failure condition like this. My opinion, that logic is absolutely ludicrous, and the failsafe should always deploy the airbag in a collision.

If this sensor failure scenario occurs, the child-seat should be relegated to the rear and not compromise the safety of a potential front seat passenger. So what if the passenger airbags go off and there no one seated in the front passenger seat?

"The needs of the many outweigh the needs of the few" as Spock says.
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Tuesday, July 4th, 2023 AT 11:11 AM

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