Auto shoulder belt difficulty

[Phil Andrus]

Our '94 Legacy has automatic shoulder belts. When they operate
properly, they slide forward when the ignition key is off and the door
is open and slide back when the door is closed and the ignition key is
on. Beginning a month or so ago, the driver's side belt began to
hesitate in both the open and closed position. Now, it rarely moves,
staying, fortunately, in the closed position. My Haynes manual does not
discuss this feature nor is it included in the wiring diagram. Here's
what I need to know: the components in this system, their location, and
at least a basic circuit diagram or description.

Phil

 

[strchild]

I had a non-functioning, automatic, passenger side shoulder belt in my '89
XT-6 when I bought it. Turned out to be a poor harness connection. In
diagnosing the problem, I started first with the dissected Legacy's down at
the local u-pull it yard to see how Mr. Subaru had designed his shoulder
belt system... Apparently, in the Legacy cars I inspected (no XT's to be
found in the yards in my area), there is a seat belt control computer in the
trunk area of the sedan, or back behind the driver's rear strut-mound,
whatever you call it bump in the cargo area of your wagon variety. The
harnesses from the auto seat belt assembly end up there. In my XT-6
however, turns out the control unit was housed in the side of the car, right
behind the passenger door, behind the molding with the passenger armrest
under the non-moving side window.

Never finished diagramming the whole layout for the auto shoulder belt as I
had success before I needed to, but from what I recall, there is a switch to
tell the system when the latch reaches the front position, one to tell the
system it has reached the rear position, circuitry to tell the computer
whether the belt is plugged in or not, and electrical for the motor. This
stuff all runs to a control unit, housed in a gray metal box slightly larger
than the diameter of a 3 x 5 card, and an inch or so thick. One end has a
large, white, 17 pin harness connector while the opposite end has a white, 7
pin harness connector. The box has a sticker on the top that says, "P/B
CONTROL UNIT" a Subie swish logo, "88013AA041" "152000-0341" "12V" "DENSO"
"MADE IN JAPAN". I apologize but I can't remember anymore the exact year
Legacy this unit came out of, but I do remember it was early ninties, so
should be similar to what you have.

I was able to determine that the seat belt motor was fine by undoing it's
harness and hooking a 9V battery directly to it. Polarity one way, then the
other, and sure enough, the dead belt latch went and came, so it wasn't the
motor.

Anyway, to short cut a story that spans an afternoon tracking down all
connections involved, verifying each connector is clean and harnesses firmly
plugged back into place, haven't had a problem since.

Seems a fair amount of circuitry just to control the forward or back travel
of the mechanism. Course, it's nice the seat belts don't zip forward when
the door sensor thinks the door is open and the car is driving down the
road, so maybe that has something to do with it! (-;

Good luck with your hunt.

~Brian

 

[S]

Hi Phil!

Our '94 Legacy has automatic shoulder belts. When they operate
properly, they slide forward when the ignition key is off and the door
is open and slide back when the door is closed and the ignition key is
on. Beginning a month or so ago, the driver's side belt began to
hesitate in both the open and closed position. Now, it rarely moves,
staying, fortunately, in the closed position. My Haynes manual does not
discuss this feature nor is it included in the wiring diagram. Here's
what I need to know: the components in this system, their location, and
at least a basic circuit diagram or description.

Alas, an all-too-common problem with these cars. I can probably
provide you with that section of the manual, but I can offer
reasonable assurance that it is the mechanism it's self that has
failed. (I've replaced way too many . . .)
Best solution, assuming that the latch is all of the way in the back
position (seat belt light is off), is to simply unplug the damned
thing, and work the shoulder belt manually. Connector is behind the
lower B-pillar cover. For easier access, remove the drivers seat. You
will also need to remove the door sill plastic on both doors. From
there, just grab the trim piece near the top and pull it off. This
seems a bit unlikely at first, but once started it'll come easily.
IIRC, there is a way to manually operate the drive gears once the
cover is off; you might be able to use that to move the latch all of
the way back if it isn't already there. Once unplugged, the seat belt
light will stay off, and the warning chime will be blissfully silent.
If you decide that you must have the automatic seat belt, you will
need to replace the entire thing. Pull the lower B-pillar cover as
described. Pull the upper part as well (push-in clips, and maybe a
screw or two), loosen that side of the headliner (more clips, be
careful or you'll crease it), and remove the A-pillar plastic (again,
hidden clips). Remove the 6mm screws holding the track at front and
along the top, and the larger hardware at the rear. Replace and
reassemble. Hint: remove any clips that remain in the sheetmetal and
replace on the plastic before installing.
A salvage yard will probably charge $75-$100 for one of these. I don't
even want to guess what Subaru want's for one, but I'll bet it's a
significant percentage of the value of the car . . .
Hope this is helpful.

ByeBye! S.

Steve Jernigan KG0MB
Laboratory Manager
Microelectronics Research
University of Colorado
(719) 262-3101

 

[S]

Hi again, Phil!

If you decide that you must have the automatic seat belt, you will
need to replace the entire thing. Pull the lower B-pillar cover as
described. Pull the upper part as well (push-in clips, and maybe a
screw or two), loosen that side of the headliner (more clips, be
careful or you'll crease it), and remove the A-pillar plastic (again,
hidden clips). Remove the 6mm screws holding the track at front and
along the top, and the larger hardware at the rear. Replace and
reassemble. Hint: remove any clips that remain in the sheetmetal and
replace on the plastic before installing.

Had a look at mine last night. In all likelihood, you will also need
to remove the grille to access the headlight assembly (not for
adjustment; only to remove). It's held on by way of two or three kinda
funny clips, and possibly a screw. To release the clips, reach in with
a small standard screwdriver and depress the little lever (use a
flashlight; you'll see what I'm talking about) while pulling outward
gently. Stuff a piece of cardboard or whatever comes to hand in behind
the clip once you loosen it, or it will snap back in when you move to
the next one.

Bye! S.


Steve Jernigan KG0MB
Laboratory Manager
Microelectronics Research
University of Colorado
(719) 262-3101

 

[nobody >]

Hi again, Phil!



Had a look at mine last night. In all likelihood, you will also need
to remove the grille to access the headlight assembly (not for
adjustment; only to remove). It's held on by way of two or three kinda
funny clips, and possibly a screw. To release the clips, reach in with
a small standard screwdriver and depress the little lever (use a
flashlight; you'll see what I'm talking about) while pulling outward
gently. Stuff a piece of cardboard or whatever comes to hand in behind
the clip once you loosen it, or it will snap back in when you move to
the next one.

Bye! S.


Steve Jernigan KG0MB
Laboratory Manager
Microelectronics Research
University of Colorado
(719) 262-3101

Steve-- wrong post.....

 

[S]

Hi Nobody!

Steve-- wrong post.....

Sure 'nuff.

"Measure twice, cut once . . ."

Thanx!

ByeBye! S.


Steve Jernigan KG0MB
Laboratory Manager
Microelectronics Research
University of Colorado
(719) 262-3101