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I have just completed my bench seat swap and thought I would share what I learned. I have a 2006 double cab that had heated leather bucket seats and replaced them with a 40/60 split bench seat (cloth) from a 2006 access cab.

I found my bench seat using car-part.com which worked out really well. One thing I learned from talking to a couple salvage yards is that, if you ask for a seat, you only get the seat and whatever is bolted to it. In the case of the Tundra bench, the center seat buckle is bolted to the floor of the truck and not the seat so that buckle did not arrive with my seat. I was able to get one for $18 from the local Toyota dealer. Also, it is important to verify that all parts that should be attached to the seat actually are. The first salvage yard bench seat I was interested in turned out to be missing the center belt assembly all together.

I found along the way that Tundra's are more unique than I expected. Since both my truck and the bench seat donor truck were 2006 Tundras, I was hoping everything would be compatible. However, I ran into both electrical and mechanical issues.

First, the mechanical. I believe this difference in rail length is due to the different B pillars between the access cab and double cab.

The bolt spacing on my bucket seat rails was 18 inches across and about 19 inches long. Both rails on the seat were the same. This was the same as the inner rail on each half of the bench seat which was good. However, the outer rail on each side of the bench seat was about 2.25 inches shorter at the back of the rail than the rail of my bucket seat. This meant that only 3 of the 4 holes on each seat half lined up. Luckily the front two holes lined up, as they are at an angle and have a locator pin that also must fit. For the back outer bolt hole on each side, a friend made an adapter to span the gap. The adapter bolted into the factory bolt hole in the floor, and the seat bolted to the adapter. I believe these were 1/4 inch steel and look pretty solid. After installing those, the bench seat halves were fully attached.

Before I bought the bench seat that I did, I had looked at a bench seat out of a 2004 Tundra. On that seat all the rails were too short, so I believe that if you have a 2005 or 2006 Tundra the seats can only be swapped between other 2005-2006 Tundras. If you want the seats to bolt in without any fabrication, the seats will have to also be from the same cab style (double cab or access cab).

And then there was the electrical. All the references I make to connectors and wiring are from the 2005 Toyota Tundra EWD (Electrical Wiring Diagram) which can be downloaded as a PDF as mentioned in this thread (2nd post). Pages 46, 517, and 518 are especially relevant to this project.

The driver side plugged in and worked fine without any issues. Both the airbag position sensor and the seat belt switch work fine. However, the passenger side of the split bench did not go as smooth. The passenger side has an "Occupant Classification ECU" under the seat which basically decides if you weigh enough to activate the airbag. Both the passenger bucket and passenger half of the split bench have this computer. Both styles of seat also use the same 6-pin connector BS1 to connect between the seat and the truck. However, the pin outs of the connectors are different! This means, if you simply plug the bench connector into your truck as I did, your truck will no longer start. Instead, it will blow the IGN1 fuse under the dash. This is because the incorrect wiring causes the ignition power supplied to the ECU to be shorted to ground. I am not sure why, but the Occupant Classification ECUs are different. In the bucket, this ECU connects with connectors O10 and O11. However, the ECU under the split bench itself is a different shape and also has a different single connector (black 18-pin) that is not mentioned anywhere in the EWD. Likewise, the wiring associated with the BS1 connector for the split bench is not mentioned anywhere in the EWD.

I did not want to leave the BS1 connector disconnected and lose the passenger airbag. So it was time to adjust the wiring.

I did this by making a wiring adapter to make the pin outs compatible (so the ignition power connects to the ignition power, the ground connects to the ground, etc). I used the male side of a BS1 connector from a split bench seat (to mate with the existing connector at the seat) wired to a female side of a BS1 connector from a bucket seat (to mate with the existing connector at the floor of the truck). Even though the pin outs are different, 5 of the 6 wires are the same color between the two seat styles so the adapter is easy to wire (which is nice since I could not find it anywhere in the EWD). The one wire that is different is the battery power (+B) which is white-red on the bucket seat side and black-blue on the bench seat side. The other wires are a direct match (IG, GND, FSR-, FSR+, DIA).

After plugging the adapter in between the truck and the seat, all is well. The weight sensor in the passenger seat functions again, and activates the airbag when an adult is sitting in that seat.

And that is how I got a 6-seat Tundra.
 

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Mech. Engr. / Mechanic
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Good thread. Points sent.
 

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Thanks for this write up. I need to buy new bench seat for my tundra and rewire it, just like you did.
 

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Hi, based on your description, detail, and pictures, i bought a bench seat out of an 06 access cab to put into my 06 d/c. I love it when people are as detailed as you've been. I now have possibly a stupid question, but i'm stumped for the moment. i unbolted my center console today to start the swap and did not expect there to be so much stuff under it, and also expected the carpet to continue from one side to the other. What did you do with the now vacant center console space where the sixth occupant will put their feet? Thanks so much for your time.
 

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Discussion Starter #5
Hi, based on your description, detail, and pictures, i bought a bench seat out of an 06 access cab to put into my 06 d/c. I love it when people are as detailed as you've been. I now have possibly a stupid question, but i'm stumped for the moment. i unbolted my center console today to start the swap and did not expect there to be so much stuff under it, and also expected the carpet to continue from one side to the other. What did you do with the now vacant center console space where the sixth occupant will put their feet? Thanks so much for your time.
I should have mentioned that in my original post.

I too was sad to see the hole in the carpet area. I ended up using a rear seat floor mat and just laid it horizontally across the gap. Since it's the same carpet color it actually looks pretty good.

After I removed the center console that was between the bucket seats, and before I put the bucket seat in, I removed the mounting brackets, put their bolts back, and then coverd the whole area exposed by the hole in the carpet (as well as anywhere I could reach using that hole) with Dynamat. I did that for both sound and heat insulation since the transmission is right below that area.

Thanks!
 

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Very cool! I'm looking to do the same thing right now. It's hard finding a nice front bench. Bummer about the hole/carpet. I'd want mine to look 100% factory; havig a hard time picturing how yours looks with a floor mat in that spot.

Thanks for the write-up! :tu:
 

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Beer Me
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i would kill to have buckets in my 04 haha. im the other way around. i mean i love the road head edition seats but i wish i had buckets.
 

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i would kill to have buckets in my 04 haha. im the other way around. i mean i love the road head edition seats but i wish i had buckets.
I went to buckets last year and got rid of my bench seat earlier this year for a case of Guiness.... If only you would've seen my post. Plus I'm only a hop skip away from you in Antioch.

It's definitely nice to have buckets and a center console. It made the transfer case swap easier because of the shift lever coming through the floor.
 

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Good info on this thread. Considering an opposite switch... :)
 

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Hello I'm looking forward to do same switch on my 2006 crew cab tundra. Looking for someone who has bench seat and wants bucket seats so we can do trade.
I have grey cloth bucket seats in excellent condition, with air bags (truck has only 55k). I live in Sacramento California we can meet and do trade. If you need what I have contact me. Thanks
 

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Do you still want to do switch?
I'm not Anchorage Alaska. I have 2 sets of seats I just can't get the front seat powered. Going from non powered bench to bucket.....
 

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If anyone has a front seat bench for an 05/06 Double Cab (or even Access Cab) with the dark grey fabric, I'd be interested in this. Hoping to do this very conversion.
 
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