Hi Thankyou for getting back to me , currently my car has a drivers buckle so Ive no feed in it to the occupancy sensor it’s just plugged into the loom of the car under the seatOn the airbag side the Yaris is only two wires. A feed to an igniter and a return. The earth on the recaro wiring is not used. I have asked recaro dealers if they are polarity sensitive and they say “ask recaro” recaro say “ask your authorised recaro dealer”. I do not believe they are and I have found this information regarding this.
Amanda. As far as the seat belt buckle is concerned it is normally closed and when the buckle is inserted it is open circuit. I have not been able to get a voltage reading from the circuit though, even with weight applied to the occupancy sensor. The system is working but I expected to see a switched 12v feed to it. In theory if the two wires were disconnected and isolated it would be an open circuit and the car would think the seat belt is done up. Not relevant for my set up but does this help?
GR Yaris Recaro CS sportster with airbags
- Thread starter GJR
- Start date
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- #24
Drivers one works the same as the passenger one. It even has the 4 pin plug on it. Checked it today by swapping it over and it all works.
SpeedCAD
New member
- Feb 8, 2024
- 9
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The workshop manual states the following for the conditions of the occupancy sensor pad. You can get cheap occupancy sensors off the internet that would match this very wide tolerance specification, so then it would be just making sure you use the same plug as the Yaris loom has on the car
SpeedCAD
New member
- Feb 8, 2024
- 9
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Not true… If you have no occupancy sensor plugged into the passenger seat, then the system believes no one is in the passenger seat and will not deploy passenger airbag(s) in a crash.
Some folks have wired theirs up to think that someone is always in the passenger seat, so all the airbags will always deploy in a crash. Probably by placing another couple of resistors in addition to the airbag one. One under 100 Ohm to fool the occupancy system, and another over 10K ohms to trick the seatbelt fastened system. This can annoy insurance companies as they will have more damage to repair if the passenger dashboard airbag also goes off in a crash with no one in the passenger seat…..!
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- #27
Fantastic information and that confirms what I am seeing. The occupancy sensor with me sitting on the seat is 30 ohms, with my wife it is 40 ohms. The more pressure exerted the lower the resistance. The occupancy sensor is not available from Toyota. I am using one from Jaguar / Land Rover used on multiple models from the XF to the Evoke. It reads 18-20 ohms with me and 30 with Dawn. I was going to run the occupancy sensor with a 10 ohm resistor to bring it to Toyota values. Your information though is really helpful because even without the resistor the vehicle will know there is someone in the seat. The seat belt will then remain as OEM and work exactly the same.
I have just purchases another passenger seat buckle because it’s shorter and will sit better against the recaro seat. It also means I can at any point return the car to standard as the only modification to the cars loom is restricted the the occupancy sensor which is part of the seatbelt buckle not the cars loom. The Jaguar landrover occupancy sensor will connect to the seat belt buckles loom using a AMP super seal 1.5 connector. Only £46 from Toyota for the complete buckle.
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- #28
Test fitted the seats with the JCR hardware today. What a massive difference to the feel of the car. It really is night and day vs the standard seat position. I don’t feel I am too far away from the wheel anymore.
The install went fairly smoothly, just one bolt which fixes the JCR frame to the car has to be put in, in a particular order otherwise the seat rails prevent you from mounting it later. In and out a few times to work that one through. The seat buckle on the drivers side is a passenger side one so it is shorter than the OEM drivers one and works much better with the recaro seats. Airbags were happy and there were no fitment issues. Next is to get the passenger side fully in before taking it all out again for them to be trimmed.
The install went fairly smoothly, just one bolt which fixes the JCR frame to the car has to be put in, in a particular order otherwise the seat rails prevent you from mounting it later. In and out a few times to work that one through. The seat buckle on the drivers side is a passenger side one so it is shorter than the OEM drivers one and works much better with the recaro seats. Airbags were happy and there were no fitment issues. Next is to get the passenger side fully in before taking it all out again for them to be trimmed.
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- #29
Test fitted the passenger side today. Airbags good, fitment good but the Toyota conduit is a little tight and pulls against the carpet when I move the seat. Rerouting helped but it would be better wrapped in felt loom tape. Occupancy sensor worked but when out for a drive it was apparent it was not always registering the passenger unless they really sat back in the seat. A bit of testing tonight and simply positioning the sensor further forward will resolve the problem. Where you think you exert weight on the seat is quite different from the reality. It will require re routing the cabling but otherwise not too big a job. I made the mistake of shortening the cable for its current position. Hopefully there is enough to route the new way.
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- #30
That’s the final test fit complete. Changed the location of the occupancy sensor from where my finger is to the new location. Removed the conduit on the wiring from the seat buckle and replaced with felt loom tape. Gives more clearance so it slides freely and is more secure than the electrical tape used by Toyota to secure the wire to the buckles fixing.Put the seat back together and fitted into the car. It all works exactly as the standard seat would. Occupancy sensor output is well below 100 ohms at 15-20 so the car knows someone is sitting in the seat which resolves the forward facing passenger airbag issue. All plugs directly into the cars loom with the standard Toyota plugs. Next step is to re trim the seats before the final fit.
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- #31
A bit more testing on this showed up a problem. If you are fortunate enough then your Mrs may not be heavy enough or wide enough to reliably trigger the occupancy sensor. It works with me all the time but not with her. I have been playing with this and have found the issue to be the density of the foam on the recaro seat. It’s quite soft and what is happening is the foam is compressing and deforming the sensor but not to the point that it makes a reliable contact. Put more weight on it and it’s not an issue. The solution I thought was to put it under the seat foam but this had similar results. Today I have added a thin 2mm layer of rubber between the seat base and the sensor and this seems to have resolved the issue. The final solution maybe some 3mm dense foam and then trim a little of the low point of the seat foam
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- #32
Finally got this sorted. Put the occupancy sensor directly onto the recaro seat base and fix it using double sided tape, then fix to the recaro seat foam some medium density foam PE pads. 5mm thickness works nicely as it’s not so sensitive that putting a bag on the front seat will set it off. This simply allows the sensor to be activated because the recaro seat foam is too soft to do so. The 5mm thickness cannot be felt through the seat foam either. That’s a wrap, it took a while but it’s done.
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- #34
Why they don’t supply that part separately I don’t know. It’s good to see how that’s fitted. Just on top of the foam. What I found was the foam on the Toyota seats or Jaguar etc (production stuff) is denser than the foam used in the sportster CS so it would not work on top of the foam and had to go directly onto the seat base. Your pole positions must be a firmer material. Awesome that it all works as standard now. Looking at that seat base I would think it would be easy to remove the one out of the OEM seats if you wanted to. There is always the risk that you just mess up the seat though.
The drivers side seat belt is a webbing type belt to buck where the passenger side is a metal bracket. Using another drivers side one or removing the rubber sleeve will allow it to pass through the hole in your seats and be far more flexible.
Hi yes it would actually come off the foam very easily but as you no it’s not cheap and I didn’t want to break anything , so cut it out rather than peel it , but I think it wiil peel very easy
My seats are solid I did fit some neoprene to shell seat to cusion it and my seat foams are pretty thin in that area where it sensors but my sensor is on the base as I haven’t got proper foam on poles so no where to mount on top of foam
Ive got a hybrid buckle as it’s got all the wiring for the sensor and it’s flexible I fitted it to my original seat to cheack it was working before I ordered the seat foam , ours are just solid be cause are passenger seats aren’t height adjustable unlike the GR sport which is what my buckle is off
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I need that for my pole positions too
What exactly did you buy?I bought the seat foam and the occupancy sensor is attachedI need that for my pole positions too
A GR Yaris original seat seat foam? Sorry for asking dumb questions
Yes as annoying as it is that’s the only way to get a genuine occupancy sensor
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- #40
Another alternative is a sensor from a Range Rover evoke. The drawback is the connector is not the same but there is a solution. Purchase a seat belt buckle £45 and a AMP super seal connector. You can then change the connectors to the AMP connector but you are not modifying the cars loom and can return to standard easily. It’s a cheaper way but the best way is what Amanda has done. I have had my set up on for a few weeks now and it’s proving reliable
