What's the weight on the passenger seat sensor? Iphone sets off airbag/seatbelt chime

[mattles]

thats interesting as hell. :O

[frs23]

hmmm Interesting.. Guess the RF from the cellphone is triggering the sensory system. It would be interesting to disable the all the RF to see if it still triggers it. ie turn on airplane mode on the phone. ... after just turn on the wifi and/or bluetooth to see if that does anything.

Let us know. I'm curious.

[ichitaka05]

Originally Posted by Boosted2.0

Its not a weight sensor - its a new technology that utilizes an electrical capacitance based sensor. It uses electrical capacitance to measure the body mass of an individual sitting there. Hence electronic devices that transmit like cell phones may give false readings. By the same token however, a 200 pound lump of platic would probably not turn the light on.

If you make your passenger piss them selves - it will actually set a DTC. (Seriously - it has a code that sets for the passenger seat cushion being wet)

Someone w FRS test thing out!!! It doesn't have to be 200lbs lump of plastic. lol

[Boosted2.0]

Originally Posted by ichitaka05

Someone w FRS test thing out!!! It doesn't have to be 200lbs lump of plastic. lol

I already have. My computer bag weights about 35 lbs and does not trigger the light. My Iphone does.

[Boosted2.0]

Originally Posted by frs23

hmmm Interesting.. Guess the RF from the cellphone is triggering the sensory system. It would be interesting to disable the all the RF to see if it still triggers it. ie turn on airplane mode on the phone. ... after just turn on the wifi and/or bluetooth to see if that does anything.

Let us know. I'm curious.

I'll give this a test tonight.

[dvlnsyde]

I used to use a Chimex seat belt latch in my MINI. Basically it is the just the metal part of the seat belt you place in the receiving end and the car thinks the seat belt is latched. It was around $20 but well worth it as I place many things in the passenger seat.

[Calum]

I can see the first tsb coming soon

[Boosted2.0]

This is the Owners manaul text on the matter:

Occupant detection system

The occupant detection system sensor is installed under the seat upholstery
and monitors the position and posture of the front passenger. Using this
information, the occupant detection system determines whether the front
passenger’s SRS frontal airbag should be deployed or not.
If the front passenger’s seat cushion is wet, this may adversely affect the
ability of the system to determine deployment. If the seat cushion is wet, the
front passenger should stop sitting on the front passenger’s seat. Wipe off
water from the seat immediately, let the seat dry naturally and then check
the SRS warning light as follows.

●

If the SRS warning light illuminates, keep the seat dry until the warning
light turns off. If the SRS warning light stays on even when the seat has
dried, do not allow anyone to sit on the front passenger’s seat and have
the system checked by your Scion dealer.

●

If the SRS warning light does not illuminate, check that the front passenger’s
frontal airbag ON and OFF indicators work properly. If the indicators
do not work properly, do not allow anyone to sit on the front passenger’s
seat and have the system checked by your Scion dealer.

74

1-7. Safety information

Also, if luggage or electronic devices are placed on the front passenger’s
seat, this may adversely affect the ability of the system to determine deployment.
This may prevent the front passenger’s frontal airbag ON and OFF
indicators from working properly. Check that the indicators work properly.
When the OFF indicator turns off and the ON indicator illuminates, the front
passenger’s frontal airbag may deploy during a collision. Remove luggage
and electronic devices from the front passenger’s seat.
NOTE
This device complies with Part 18 of the FCC Rules. This device may cause
interference. If this device causes interference, consult the nearest Scion

dealer. Also, for maintenance of the system, consult the nearest Scion

This is what the NCF has to say about the sensor:

1. OUTLINE
(a) The occupant classification system uses an electrical capacitance-based sensor located in the seats to monitor the physical build of a passenger seat occupant by its electrical capacitance. A determination on whether the seat is occupied, a child seat (CRS) is present, or the seat is empty, is made according to the monitored physical build of the passenger seat occupant and the state of the seat belt buckle switch RH.
(b) This system restricts the deployment of the instrument panel passenger without door airbag assembly.
(c) The system informs the driver of the result of the judgment through the use of the AIRBAG ON/OFF indicator lights.
(d) This system consists of the occupant detection ECU, occupant detection sensor, AIRBAG ON/OFF indicator lights, front seat inner belt assembly RH and airbag ECU assembly.
2. PRECAUTION
(a) To avoid potential death or serious injury due to the front passenger occupant classification system not detecting the conditions correctly, observe the following:
(1) Wear the seat belt properly.
(2) Do not put a heavy load in the front passenger seatback pocket or attach a seatback table to the front passenger seatback.
(3) Do not put weight on the front passenger seat by putting your hands or feet on the front passenger seatback from the rear seat.
(4) Do not let a rear passenger lift the front passenger seat with their feet or press on the seatback with their legs.
(5) Do not put objects (shoes, umbrellas, or other items) under the front passenger seat.
(6) Do not recline the front passenger seatback so far that it touches the rear seat. This may cause the AIRBAG OFF indicator light to illuminate, which indicates that the passenger airbags will not deploy in the event of a severe accident. If the seatback touches the rear seat, return the seatback to a position where it does not touch the rear seat.
(7) Do not spill liquids on the front passenger seat. If a liquid is spilled, the seat should be dried out immediately.
(8) If you get the front passenger seat wet, have the system checked for damage at the dealer.
(9) Do not remove the seat or disassemble it.
(10) Do not place any accessories (e.g. audio amplifiers) other than official accessories underneath the front passenger seat.
(11) Do not put magnets near the seat belt or buckle.
(12) If you put electronic appliances on the front passenger seat, the determination might not be performed correctly.
(13) Do not use the front passenger seat while the SRS warning light is lit and the vehicle is taken to the dealer.
(14) Please take the following precautions when a child sits in the front passenger seat.

• Do not place anything on the seat other than the child and the CRS.
• Do not allow more than one child to sit in the front passenger seat.
• Do not install a CRS while the seat is wet.
• Do not place electronic appliances on the seat.
• Occupants of the rear seat should not put their hands or feet on the seat cushion of the front passenger seat, nor should they touch the child in the front passenger seat for an extended period of time.
• Move the seatback to confirm that the seatback and the forward/backward position of the front passenger seat are properly locked.

(15) Please take the following precautions when an adult sits in the front passenger seat.

• Do not use a blanket, seat cushion, seat cover, seat heater, massager, or anything similar.
• If wearing thick clothing, remove the clothing or move the rear seat.

(b) Keep the front passenger seatback as upright as possible when the vehicle is moving. Reclining the seatback excessively may lessen the effectiveness of the seat belt.
(1) Make sure that the AIRBAG ON indicator light is illuminated when an adult sits in the front passenger seat. If the AIRBAG OFF indicator light is illuminated, ask the passenger to sit properly, all the way back against the seat, with legs comfortably extended, and to wear the seat belt correctly. If the AIRBAG OFF indicator light remains illuminated nonetheless, let the passenger sit in the rear seat. When it is unavoidable to sit in the front passenger seat, ask the passenger to move the seat as far back as possible and remain properly seated.
(2) When it is unavoidable to install a forward-facing child restraint system on the front passenger seat, install the child restraint system on the front passenger seat in the proper order.
(3) Do not kick the front passenger seat or subject it to severe impacts. Otherwise, the SRS warning light may come on to indicate a malfunction of the detection system.
(4) Child restraint systems installed on the rear seat should not come into contact with the front seatbacks.

I particularly like this part:

If wearing thick clothing, remove the clothing or move the rear seat.

"Sorry babe - you're going to have to take that shirt off. Its right in the manual - see - I have highlighted and laminated that section for your convenience. "

It probably won't work, but hell, its worth a try right?

[ichitaka05]

Originally Posted by Boosted2.0

I already have. My computer bag weights about 35 lbs and does not trigger the light. My Iphone does.

Cool~ thanks... & DAMN!!!! 35lbs!?!?!? That's a pretty heavy pc bag!!! What do you have? 1980's Mac?

[Guff]

You learn something new everyday...

[Boosted2.0]

Originally Posted by ichitaka05

Cool~ thanks... & DAMN!!!! 35lbs!?!?!? That's a pretty heavy pc bag!!! What do you have? 1980's Mac?

It is a older Dell which is pretty heavy but the real bulk comes from all the other stuff. (GPS, flashlights, pressure & tread depth gauges, various chargers, inverter, scan tool cable, pens, emergency coins for toll roads, business cards, spare battery, power supply, etc.)

[trackmagic]

Can you get to the connector for the seat belt? I bet if you disconnect it and jumper the connection it will think the seat belt is buckled and ignore the sensor. (Also just try disconnecting the seat belt connector in case the switch is a normally closed type)

[Boosted2.0]

Originally Posted by trackmagic

Can you get to the connector for the seat belt? I bet if you disconnect it and jumper the connection it will think the seat belt is buckled and ignore the sensor. (Also just try disconnecting the seat belt connector in case the switch is a normally closed type)

If you just put in a regular jumper it will think it us unbuckled. The switch has no resistance when unbuckled, and has over 10K ohms when buckled.

Jumping it will probably also mean the pass bag will go of in the event of an accident even with the seat unoccupied.

[Dadhawk]

Originally Posted by Boosted2.0

I already have. My computer bag weights about 35 lbs and does not trigger the light. My Iphone does.

Same here. Droid X sets it off, much heavier non-metal, non-trasmitting items do not.

At least now I know why.