This article is
ONLY for the skilled and qualified, so read this first and see if you're qualified. Airbags are explosives, and the "earth shattering ka-boom" is guaranteed to ruin your day:
https://www.nicoclub.com/archives/my-ai ... -i-do.html
Okay, if you're still here and not making an appointment with your dealer, it probably means you have a B1129 (passenger) or B1134 (driver) code for an open Side Airbag circuit in your seat. You've also probably discovered that the dealer needs to sell you a $1600+ seatback in order to fix it. That's not the dealer's fault or Nissan's, it's a lawyer thing. What you'll see here was done by me and for me on my wife's '13 SL. I will
not do it for customers, not even as side work. If you fix one of these for your neighbor, even if their airbag doesn't fail in an accident, an unscrupulous lawyer or insurance company can easily make it look like you did something wrong. So the only advice I'll offer on that count is, don't do it for others.
That said, on gen5 Alties, those two codes (and occasionally B1132/33/36/37 short-circuit codes) are always caused by wiring. The harness can chafe or pinch which occasionally causes shorts instead of opens, but the gen5's have some very specific harness-routing issues in and under the seat which you'll see as we go along. I've seen plenty of them, and I have yet to see a failed side airbag module. The problem does occasionally happen to other models, and this same basic procedure will usually apply.
So let's get started. You'll need the following supplies:
1) About 4 feet each of two different color wires, preferably the soft "super flex" type
2) At least 4 red solder-shrinks of the type shown in the article referenced above
3) About a foot of 1/4" or 3/8" split plastic loom, plus electrical tape
4) 4" or 6" zip-ties
5) Several small foam pads, preferably closed-cell
6) Bottle of white vinegar
The latter is because the under-seat airbag wires are steel and need to be chemically "kilned" in order for the shrinks to bond properly with the differential metals. The same technique works for aluminum as well. Just dip the stripped ends, let them sit about 5 minutes, then wash them clean with water. This will open pores in the steel or aluminum that allow solder to bond to it.
You'll also need the following tools:
1) Wire cutter/stripper
2) T50 torx driver for the seat attachment bolts
3) Small hook tool for removing the upholstery J-hooks
4) Medium canted prybar for popping the seatback board
5) Electric drill for making the new wires into "twisted pair"
6) Bic lighter or a heat gun for melting the solder-shrinks
The first step is to remove the seatback board as shown in Figs 1~3. Do this while the seat is still bolted down, it's much easier. Start at the bottom of the board by popping loose the two long, white plastic pawls shown in Fig 3. Then insert the prybar carefully under one side of the board and locate one of the big plastic center hooks. Force inward on the hook to release it, slide the board sideways to release the other hook, then pull the board downward to clear the top hooks:
Once the board is removed, remove the four T50 seat bolts. The two in front will be obvious underneath "pop out" plastic covers, the two in the rear are sunk into the seat tracks as shown in Fig 4. Then pop all the lower J-hooks as shown in Figs 5~6. I always found it easier to pop them when I can move the seat around to get good angles with my hook, but that's a preference. There's nothing wrong with popping the J's first if you don't have strong hands:
Looking at Fig 6, you can now see where most of the problems with these bags originate. Notice the harness makes two bends on its way to the bag, one upwards and then across where it emerges from underneath the seat, then a spiral going around the outboard frame rail to get to the bag. Both of these "wiggle" a bit every time the back is tilted. You can see that the harness is also tightly-fitted beneath the seatback board, so it's very easy for it to get pinched or flattened by the board. That's really all it takes to cause a resistance issue.
Once the seat and the J's are all loose, tilt the seat backward and remove the lower run of the airbag harness from the seat bottom as shown in Figs 7~9.
BE SURE TO GROUND YOURSELF TO THE CAR BEFORE TOUCHING THE CONNECTOR. THROWING A STATIC SPARK AT THE CONNECTOR CAN BLOW THE BAG.
Once you have the wires loose all the way to the bag, mark one of the two wires at the bag with a sharpie before cutting the harness loose from the bag, leaving some ink on both sides of the cut. The OE wires are both the same color and the squib circuit inside the bag
shouldn't care about polarity, but I'd hate to get into a crash and discover that for some reason it did. So mark it at the bag before cutting, then trace it to the connector after removing the sheath and mark it at the connector before cutting that loose. Cut the bag end loose first, and
AGAIN, DISCHARGE ANY STATIC BEFORE CUTTING. Make the cut as close as practical to the bag, leaving yourself just enough wire to strip the ends and apply shrinks. Do the same at the connector end, and cut loose and prep the white nylon restraint as shown. Twist your new wires into a pair and finish prepping and routing the under-seat portion of the repaired harness as shown in Figs 10~15. DON'T FORGET TO KILN THE STEEL WIRE ENDS BEFORE MAKING THE SPLICES. Put the connector in place but don't plug it in yet, that gets done last. If you're using a Bic for the shrinks (and that's definitely faster and handier than a heat gun), simply keep the shrink in the blue part of the flame. Only the orange part gets sooty and makes a mess.
Once you're done under the cushion, route and loom the repaired wires a section at a time so you keep it neat and don't leave a lot of extra wire flopping around. Remember, it's crappy and inadequately-protected routing that causes these failures in the first place.
Finally, make your connections at the bag. AGAIN, DON'T FORGET TO KILN THE STEEL WIRE ENDS BEFORE MAKING THE SPLICES. Make sure you loom the wires completely where they spiral around the frame below the bag, and protect them with foam wherever the seatback board might squeeze them. Those spots are where a lot of failures happen.
One final note. There is one other occasional failure spot, although it isn't so common. However, it's pretty much impossible to diagnose without first knowing the bag wires are good. That's the flexible loop of body harness where it rises to connect to the seat. If you still get intermittent codes after repairing the bag wires, you'll find the issue in that loop of harness. Fixing it is easier because it's copper wire to begin with and you can disconnect the bag during repair, so just disconnect the battery and then strip both wires back in that looped section to replace them.
Hope you find this useful. Happy motoring!
