Tacoma Occupant Sensor Bypass

Okay so I managed to get my laptop working with Techstream Version 9 (Toyota's software), I got the .25W 2 ohm resistors installed on pass and driver wire harnesses by clipping the existing airbag cord from the old seats and installing in the new (using the resistor to complete the circuit) so I have no airbag code showing. I then salvaged the whole occupant sensor system from the old passenger seat and it is currently sitting on the floor behind the new seat which I installed.

I could find no way to override the system using techstream Version 9, I know they are on about V. 17 or so now...I'm not sure if you can in later versions but here is my fix for getting my airbag system to stay ON without the sensors in the seat.

Let me just give a warning too, I don't have kids, will never have kids in my truck. I do not operate on hypotheticals so don't even try.

I have uploaded a picture of one of my sensors, I labeled it how I will be referring to it. I made a mistake at first thinking you needed to press down on the sensor body in order to register weight, it works....but you will crack the sensor body housing if you put too much and this is also not how it works. The plate is attached to the sensor body underneath and I believe it registers the weight in regards to the magnetic detector and how close or far it is from it. It will register up to -35lbs if you pry the red from the green circle (I added these for reference) and for the fronts they go up to I believe 65lbs and the rear up to about 85 lbs. I tried to calibrate them after prying to get a negative reading so I could start out with about 70 lbs + once I let go however if you try and calibrate them with a negative reading it will say "sensor NG" which I assume means "not good." As soon as you reach over 87 or 89 lbs or so your airbag system will switch over to "ON." You only need to use two of your four sensors, all 4 do not need "weight" or pressure added to them. You will see my fix was to add hose clamps with some cable ties for added protection (I may throw another hose clamp on there just to be safe). This works for me though, Airbag system is on, only downside is if no one is in the seat the seatbelt indicator on the dash will flash constantly. (I turned off the seatbelt chime using tech stream).

Here are some pictures of my computer screen with the weight added by the hose clamps so you can see the voltage difference and maybe someone can reengineer the bypass sensor with a switch.

 

I got my passenger seat in and everything is working as expected. I couldn't have done it in a few hours with out this thread - thanks!

 

Hey no problem man, it looks great. I can say I have been driving it like this since the post and airbag is still on with no problems. Highly suggest using hose clamps and zip ties as those clamps can become dislodged in a wreck. I also found a way to shove it all under the passenger seat (even though my new seat harness is lower to the floor than the original) which is nice for space in the back.

 

I am seeing some new codes that just showed up, indicating I have heated seat circuit malfunctions. I do, those parts from the stock heated seats are not ported over to the Scheel Mann seats. So that plug in the vehicle harness has nothing from the seat connected to it anymore. But this is after nearly 18 months without these codes???

B14C0
Front Right Seat Heat Sensor Circuit

B14C1
Front Left Seat Heat Sensor Circuit

@Hecticweather did you have factory heated seats?

 

Sorry, moved my questions to a new thread https://www.tacomaworld.com/threads...cheel-mann-heated-seats.775205/#post-27705471

 

@caribe makaira Do you have the schematics diagram for the front seat occupancy sensors? There is the rail position (forward/backward) on the drivers side, and the 4 corner weight sensors for the passenger seat. Thanks in advance!

 

Read this, it's for later model. Not the 2020. I don't think it has changed.

 

Awesome, thanks! I am wondering what it would take to put a "box" together that would be cleaner than clamping the occupancy sensors. Plug into the box, set your desired weight rating, translates to voltage or resistance targets.

 

Metal box with adjustable locking screw with flat surface pushing on the sensor, verified when occupant light goes off, maybe...