3rd row seat removal

[ClearlyLucid]

Has anyone investigated 3rd row seat removal? I have absolutely no use for the 3rd row and would like the additional under floor storage for tools, etc. I know the removal would be semi-permanent.

I’ve removed the driver’s seat from my BMW M5 before. It wasn’t hard. All that was required was the correct E-Star (Torx) socket/bit and unplugging an electrical connection.

I know the Gravity 3rd row has at least one electrical connection to flip down the head rests from the pilot screen menu.

 

[ClearlyLucid]

So, I did some due diligence on the 3rd row seats:

Mechanically it looks like the 3rd row can be removed fairly easily. With the covers removed you can see that the seats are anchored with 6x15mm bolts (3 each seat) and two nuts holding the center swing arm bracket. If you look closely the center swing arm bracket is two overlapping metal pieces. So, I believe the seats can be removed individually, which makes it a one person job.

Electrically each seat is wired with one plug with 6 wires. I’m hypothesizing that each seat should have a switch to detect the seat belt is latched (a logic input to the computer control unit), a pressure switch in the seat bottom to detect an occupant (another CCU logic input), and an solenoid actuator to release the headrests from the pilot screen when they’re latched in the up position (CCU logic output).

The question is would the CCU see an error if the seat was unplugged? I think it depends on the logic written in the CCU program and whether the switches are wired normally open or closed. If they’re both wired normally open, then unplugging likely not a problem. If both switches are wired normally closed or a combination or open & closed, then unplugging the seat could be a problem. I guess the next step would be to get out the multi-meter, identity which wires go to each switch, and then test the continuity to see if the switch is wired normally open or closed.

Thoughts?

 

[Kairide]

View attachment 37143View attachment 37144
So, I did some due diligence on the 3rd row seats:

Mechanically it looks like the 3rd row can be removed fairly easily. With the covers removed you can see that the seats are anchored with 6x15mm bolts (3 each seat) and two nuts holding the center swing arm bracket. If you look closely the center swing arm bracket is two overlapping metal pieces. So, I believe the seats can be removed individually, which makes it a one person job.

Electrically each seat is wired with one plug with 6 wires. I’m hypothesizing that each seat should have a switch to detect the seat belt is latched (a logic input to the computer control unit), a pressure switch in the seat bottom to detect an occupant (another CCU logic input), and an solenoid actuator to release the headrests from the pilot screen when they’re latched in the up position (CCU logic output).

The question is would the CCU see an error if the seat was unplugged? I think it depends on the logic written in the CCU program and whether the switches are wired normally open or closed. If they’re both wired normally open, then unplugging likely not a problem. If both switches are wired normally closed or a combination or open & closed, then unplugging the seat could be a problem. I guess the next step would be to get out the multi-meter, identity which wires go to each switch, and then test the continuity to see if the switch is wired normally open or closed.

Thoughts?

Or you could just unplug the wires and see if you get any errors?

 

[prgarg]

You should had bought the 5 seat version, available at a Lucid store near you

 

[RajD]

Would a mod like this void the entire warranty or just warranty related to seats? Seems like altering the electrical could be an issue.

 

[HC_79]

I would be asking Lucid if they can remove it before attempting to do anything. You’re likely to freak the system out just unplugging wires and attempting to do it yourself.

 

[ClearlyLucid]

You should had bought the 5 seat version, available at a Lucid store near you

The Dream Edition only came as a 7-seater, or I would’ve gladly gotten it without the 3rd row.

 

[ClearlyLucid]

Or you could just unplug the wires and see if you get any errors?

Yeah, that’s an option, but electrically, guessing and hoping aren’t good ideas.

 

[ClearlyLucid]

I would be asking Lucid if they can remove it before attempting to do anything. You’re likely to freak the system out just unplugging wires and attempting to do it yourself.

I tend to agree with you. A long time ago, in a galaxy far, far away I was an electrical engineer. Unplugging things without being certain is usually not a good idea. And as far as I can tell there is no way to power down the car while a door is open. Ideally, I need to talk to a tech.

 

[tmichael]

Who knows - the car could end up never having a software glitch, never show another bug and work perfectly for the rest of its life! Maybe if we “break” something, the processor will spend all of its time trying to report on non-existent seats that it won’t have time to tell the doors not to open when the fob is near!

A developer’s intentional trick is ironically circumvented!! Yay!!!

 

[bicycleguy]

I would try a set of 'Piercing Clip Test Probes'. They would allow measuring the connected signals without disconnecting the cable.

What could go wrong ?

 

[Kairide]

Yeah, that’s an option, but electrically, guessing and hoping aren’t good ideas.

You could spend days testing things or just do it the good old fashioned way and know within seconds. You’re already looking at tearing apart a $140k car anyways.

 

[Mr.Quindazzi]

I would be asking Lucid if they can remove it before attempting to do anything. You’re likely to freak the system out just unplugging wires and attempting to do it yourself.

I agree with you, which is a testament to how badly Lucid has developed it's software. I wouldn't hesitate in any other vehicle

 

[HC_79]

I tend to agree with you. A long time ago, in a galaxy far, far away I was an electrical engineer. Unplugging things without being certain is usually not a good idea. And as far as I can tell there is no way to power down the car while a door is open. Ideally, I need to talk to a tech.

Keep in mind, if you ever go to sell it and need to put the seats back in I wouldn’t even know what safety checks need to be done to ensure they’re installed properly again.

 

[HC_79]

I agree with you, which is a testament to how badly Lucid has developed it's software. I wouldn't hesitate in any other vehicle

I don’t think this would be specific to Lucid actually. Vehicles, especially EV’s are mostly computers on wheels these days and the software that is visible to us is only a fraction of the entire software stack.

The seats in particular probably have a whole bunch of safety requirements that need to be adhered to that it’s likely to freak any car out if you just start disconnecting stuff.

 

[400kwOrBust]

There are 2 things that could happen
You could get a big red warning that keeps asking you to ensure rear seats are latches, or it could do something weird with seat belts. This could be fixed by asking service center to request a bcm config change to change the car to a 5 seater, but they probably wouldn't let you do that.

I think generally you should be fine you just might need to spoof the latch.

 

[johnse]

Y'all are assuming the sensors/switches are connected as digital I/O. While you may be correct, they could also be self-contained addressable ECUs.

 

[ClearlyLucid]

Keep in mind, if you ever go to sell it and need to put the seats back in I wouldn’t even know what safety checks need to be done to ensure they’re installed properly again.

The most important thing would be the torque wrench setting for the bolts holding the seats.

 

[Mr.Quindazzi]

I don’t think this would be specific to Lucid actually. Vehicles, especially EV’s are mostly computers on wheels these days and the software that is visible to us is only a fraction of the entire software stack.

The seats in particular probably have a whole bunch of safety requirements that need to be adhered to that it’s likely to freak any car out if you just start disconnecting stuff.

Yes, and that is crazy. At the least a well sorted car would let you unplug extraneous parts with no software problems. You can definitely take the back seats out of a Tesla with no issue

 

[ClearlyLucid]

I’m going to be attending the Atlanta Lucid Owners Club event tomorrow. Unfortunately, it is not being held at the service center. Ideally, there will be a tech there who I can corner and ask. Either way I need to establish a good relationship with one of the techs for questions like this.

I kept my e39 BMW M5 running many years without ever visiting the stealer’s service department. I became a pretty good shade tree mechanic using the internet and YouTube videos, which I found more helpful than service manuals. I had done everything there was to do on that M5 other than pull and disassemble the engine. The other owners on the M5Board were a wealth of information, just like the owners on this Lucid Board are now and will be in the future. This car is so new there is limited information to answer the 3rd row question, but someone will eventually figure it out.

As many of you have pointed out, our car is basically a computer on wheels. It’s a whole different ballgame than working on an ICE vehicle. Part of the reason I didn’t replace my totaled car with another BMW is because I was tired of the high degree of maintenance, and the new BMWs are so complex you need a bunch of specialized equipment to service them. I moved to an EV because of the simplicity and performance. I just want to drive it! I’ll never go back to an ICE vehicle. Still, once in a while I feel the urge to turn a wrench…