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Some folks have had occasion where the SID will give a warning that the front
seat passenger must put their seatbelt on, but there is either no passenger
sitting there, or there is a small item like a book or bookbag. This problem is
not on all seats/vehicles. The problem is that the sensor is too sensitive, and
is in a position that compounds its sensitivity. You can fix the problem by
moving the sensor further back if you want if you follow the instructions.
Disconnecting the sensor is not recommended due to it's possible interaction
with the airbag.
ctrlz has done this modification, and has posted excellent instructions
here. I repeat them here for posterity.
PROBLEM: Passenger seat belt indicator appears in SID when
passenger seat is UNOCCUPIED
BACKGROUND: This has been included among the "List of Common
Problems" in this forum. An easy fix is obviously to hook up the passenger
seat belt when no one is sitting there. I'm not sure, but there may be
underlying safety problems related to this fault, and trying such an "easy
fix."
There is a sensor array in the bottom seat cushion which detects pressure.
This is, at least, part of a Passenger Presence Detection (PPD) system in
the 9-3. Because of the shape of this sensor, I suspect it may also be
part of an occupant classification system. I don't know how sophisticated
the airbag deployment computer is on the 9-3. The most sophisticated
systems employ PPD, occupant classification (size, position on seat,
weight, child car seat detection), and seat position sensors to help
determine the extent of airbag deployment in a crash. If the 9-3 employs
such a system, then false readings by the seat sensor could lead to
erroneous occupant classification. My dealer tells me there's no TSB on
this problem yet. So, I'm posting my solution here.
SOLUTION OVERVIEW: I have a 2003 9-3 Vector with heated seats.
Build date 06/03. Your specifics may vary.
You will be taking the lower seat cushion out of the car and repositioning
the sensor. My sensor was too far forward. If your warning light is not on
all the time, try pushing lightly on the seam which runs side-to-side in
the mid portion of the seat cushion. In my car the front tip of the sensor
was tucked up almost under that seam, so very light pressure along the
back edge of the seam (one finger, gentle push) would give me a warning
light. On hot days I'm guessing the urethane foam and leather expand
differently, and the warning would come up. With the sensor repositioned,
I now have to push firmly with my whole hand or fist to get a warning
light. No light on hot days anymore.
WARNING! If you have big hands or forearms, you may run into trouble. You
will not be removing the whole seat, just the cushion. There is a lot of
reaching into tight spaces under the seat to get the leather cover free.
Once the cushion is out, you have to separate the urethane foam from a
cloth cover which is glued along the back edge. The sensor strip is glued
to the urethane UNDER this cover. You won't be taking off the leather. The
sensor is glued at the front and back. The back is easy to free up. But
it's a VERY tight squeeze getting your finger tips to the front attachment
point (about a 12" reach). This is the part causing the false alarms, so
it needs to be pulled out of that tight spot. I have average sized hands
and thin forearms. I took my seat into the air-conditioned house to work
so my arms wouldn't sweat.
SUPPLIES (other than basic hand tools):
1) double-sided tape - I used foam tape about 1/2" wide. This is to
reattach the sensor and close up the seam you'll be opening.
2) plastic cable tie - 1/8" to 3/16" wide, stock is black, but it'll be
hidden
3) small penlight - to see under the seat and into the seam once you have
the seat off
4) Band-Aids/ paper towels - there are sharp edges on the underside of the
seat. As you work, watch out for blood on your nice seats!
TIME: figure about 2 hrs. start-to-finish. I'm gonna tell you where
all the clips are. That'll help. ALL of the measurements I give are
ESTIMATES, so don’t get out your dial calipers and flame me for
inaccuracy!
You'll be changing the seat position several times. The battery saver may
kick in while you work. If that happens, close and re-open a door so the
seat controls will function. You will not be disconnecting them.
1) Separate trim/control fairing from door side of seat. The
fairing is attached in three places. There is a round mounting boss at the
front right corner and two metal push clips along the side, one about 5"
from the front, the other about 14". Getting these off without damaging
the trim is the toughest part. Elevate the seat all the way up with the
controls. The front side clip is gold metal and can be visualized and
manipulated from under the front of the seat. The rear side clip is
identical in type, but can only be felt with your fingertips. The front
corner is held in place on the mounting boss with a single spring clip
which can be seen when you tug the seat cushion back a little. Pop this
off by sliding it sideways with a small screwdriver. You don't have to
bend it.
Now the tricky part. If you’re better than I am, you might be able to get
the side clips to pop through by working from underneath. They're pretty
tight. I ended up pulling out on the front corner while simultaneously
pushing on the back of the front side clip with the butt end of a
screwdriver. As you get the corner off the boss, the whole fairing comes
in one motion.
The seat control cable is attached to the seat frame with one cable tie.
Carefully cut the tie (not the wire!) to free up the fairing.
The side clips snap into the inside of the fairing, and hopefully don't
shear off too much plastic as you pop this thing off. The plastic may
give, and you may have to retrieve the metal snaps from the seat frame. To
reattach them to the plastic trim you may need to open up the V-shaped
clip to give it more tension. Slide them in sideways rather than snapping
from the front. Watch out for small fragments of sheared plastic which
might prevent the clip from seating properly. If you can't get it to stay
in place, you might try a little silicone to hold it. Otherwise it'll just
pop apart when you reassemble. You don't want it to vibrate or feel loose.
2) Detach leather cover from seat frame. Start by releasing two
elastic straps which hold the bottom part of the seat back as it wraps
under the rear edge of the seat bottom. There are white plastic clips on
the end of the straps which clip onto the underside of the seat cushion
support. Feel for these and remove. The front and sides of the seat bottom
leather cover attach to the seat frame with five long black plastic clips
(two sides 6" long, two front corners 2" long, one front center 9"). Start
with the front corners. A small flat blade screwdriver may help work these
free. Reposition the seat as needed for access. Sitting on it while
reaching underneath may give you some slack. Once all five are off, gently
work the front right corner of the leather over the mounting boss.
3) The front of the seat should now lift up. The heater cable comes
off the front edge. Notice how it is routed through the rectangular hole
in the frame. Disconnect the cable, also noticing how it is supported by a
clip under the seat in its mid-portion. Now run your hands along the seat
frame sides where the cover was clipped on. There are two sawtooth
projections which are spaced the exact length of the side clip. The clip
locks in between these when you put it back together.
The back of the lower cushion is held with two elastic loops at the rear
sides. Notice how they hook around onto the plastic tabs, then reach
underneath from the back and release them. Put the seat into full recline
for the last part. The back edge of the leather wraps around the back
frame and hooks into the cushion support grid in four places. With the
cushion elevated, work from the front side to unhook. It’ll still be
pretty tight even with the seat back reclined.
Last thing remaining is the sensor wire coming off the back center.
Disconnect, and remove the cushion.
4) The urethane cushion needs to be separated from the grey cloth
glued along the back edge. Using your fingers work from the center opening
for the wire toward the sides. I had to open it up about 8” total to get
enough access.
5) Take a look inside with your penlight. The sensor strip is fork
shaped with the “handle” to the front and two “prongs” pointing back
toward you. The wire attaches to one of the prongs where it is glued at
the rear. The front edge is also glued. Separate the back from the foam,
then work your fingers way in there to get the front loose. My front edge
felt like it was under the seam. I did this part in an air-conditioned
room so my arms wouldn’t get sweaty.
6) Pull the whole sensor array back about an inch. Make sure it
doesn’t wrinkle or kink as you move it. Once you have it moved back and
flattened, plug the seat back into the car and test it. You should only
get a warning when significant pressure is applied. If you were having
heat related symptoms, you might want to leave it like this for a few days
until you’re satisfied you got the sensor positioned where it works
correctly.
7) Reattach the back edge of the sensor with double-sided tape.
Close off the seam you opened with the tape as well. I didn’t bother
trying to tape the front in place.
8) Installation is reverse of removal. The rear elastic loops are
snug and barely stretch to get back on. The side clips for the leather
cover lock in between those sawtooth projections I mentioned earlier. You
may need to sit on the seat as you reinstall to gain slack. Check your
driver’s seat while you’re at it. Both side clips were not positioned
correctly on mine, and one of the front corners was hanging free. Don’t
forget the new cable tie for the seat control wiring. Put the spring clip
back on the corner of the trim fairing. Now snap the fairing back on in
one coordinated motion. It doesn’t bend very much, so you can’t do it one
clip at a time.
Check the fairing to make sure it clipped on OK and you’re finished!
