'93 Impreza - CEL 33 - Vehicle Speed Sensor (VSS)

[Brian]

Went off the road the other day and the speedo stopped working. Check
engine light came on and is reporting a 33 which checks out to be the
Vehicle Speed Sensor or (VSS).

I've been through the group here and through Google, looking for the
location of the sensor but I can't find it. Best I've come up with is
somewhere on the front differential, but after throwing the car on ramps,
crawling all over and under the car, umm, can't find it anywhere. Closest
I've come to any sort of sensor on the tranny is a round, single wire unit
that is on the third portion of the transmission, just above where the
exhaust 'Y' comes together. It is being held in place by a single 10m bolt,
which after removing the bolt, I couldn't get the stupid sensor to come out.
I got it out most of the way, but the wire is too tight to come out further
and actually has no harness that can be disconnected. Hmm. Also, the
sensor seemed to have what looked like gear oil on it after the partial
removal, but only a bit, and nothing was leaking out around it. Is this the
VSS and I just haven't pulled hard enough to get it to dislodge all the way?

I'm frustrated. I would like to fix the problem, but I don't know where to
look for the bugger.

The top of the tranny has the mechanical cable feeding from the
top-passenger side through the firewall to the back of the dash. I am
figuring if it were just a cable, how would the computer know, unless there
is a feedback from the dash, which I doubt. Sounds too sophisticated for
this car.

Would love help with this, if anybody knows.

Thanks!

~Brian

 

[1 Lucky Texan]

Went off the road the other day and the speedo stopped working.  Check
engine light came on and is reporting a 33 which checks out to be the
Vehicle Speed Sensor or (VSS).

I've been through the group here and through Google, looking for the
location of the sensor but I can't find it.  Best I've come up with is
somewhere on the front differential, but after throwing the car on ramps,
crawling all over and under the car, umm, can't find it anywhere.  Closest
I've come to any sort of sensor on the tranny is a round, single wire unit
that is on the third portion of the transmission, just above where the
exhaust 'Y' comes together.  It is being held in place by a single 10m bolt,
which after removing the bolt, I couldn't get the stupid sensor to come out.
I got it out most of the way, but the wire is too tight to come out further
and actually has no harness that can be disconnected.  Hmm.  Also, the
sensor seemed to have what looked like gear oil on it after the partial
removal, but only a bit, and nothing was leaking out around it.  Is this the
VSS and I just haven't pulled hard enough to get it to dislodge all the way?

I'm frustrated.  I would like to fix the problem, but I don't know where to
look for the bugger.

The top of the tranny has the mechanical cable feeding from the
top-passenger side through the firewall to the back of the dash.  I am
figuring if it were just a cable, how would the computer know, unless there
is a feedback from the dash, which I doubt.  Sounds too sophisticated for
this car.

Would love help with this, if anybody knows.

Thanks!

~Brian

It seems there are a few '93s with anti-lock brakes. maybe they have
'tone rings' and magnetic pickups on the wheels for VSS circuitry. If
so, running off the road could damage a sensor at the wheel or it's
wire. I've also read of metal debris getting stuck on the sensor and
confusing the system.

Carl

 

[johninky]

This car should have two VSS. One is located in the instrument
panel. If the speedometer cable or speedometer fails, so does the
VSS. The other VSS is located in the very rear of the transmission if
you have an automatic. Have no idea where located if a manual. In
the automatic it is located on the passenger-side on the rear
housing. Just a magnet so whatever you attempted to pull isn't the
second VSS. Also, and I can't remember which, but with the automatic
transmission the location of the rear VSS depends on wheter FWD or
AWD. One has it located externally and the other internally. I think
the FWd transmission has it inside the rear housing.

Thing is the transmission VSS, unless the wire broke, is almost not a
problem. What can fail with a magnet? If the speedometer cable is
not broken, focus on the VSS in the instrument panel. When I had this
problem, I just replaced the entire instrument panel with another from
a wrecking yard.

 

[johninky]

Just reread the OP and see you where off the road when this failed.
Now thinking you probably did rip the rear VSS wire off. Look on the
right side of the tailshaft for it.

 

[Brian]

Just reread the OP and see you where off the road when this failed.
Now thinking you probably did rip the rear VSS wire off. Look on the
right side of the tailshaft for it.

Okay, sorry, I forgot to mention, yes it's an automatic, and no it doesn't
have anti-lock brakes...

The aggravating part is that after searching over the entire transmission,
top to bottom, I can't find damage anywhere, just dirt. No broken wires, no
dents, no scrapes. Only single wire sensor looking part is what I
described. It looks like it could be a magnetic pick-up, going into the
final drive, and yes, it's under the passenger side of the final drive
portion of the transmission. The wire for it actually goes over the top of
the transmission and into a larger harness. No visible means to disconnect
the wire when I pull the thing out...

Looks like a trip to the junker to try pulling the sensor out all the way
over there and see how the wire detaches.

There is a VSS in the dashboard also? If that were the failing unit,
wouldn't the speedo still function?

Also forgot to mention, the transmission is flashing out a problem using the
'power' light on startup. Anybody know the means to read those flashes,
which I would assume is similar to reading the CEL?

~Brian

 

[johninky]

Okay, sorry, I forgot to mention, yes it's an automatic, and no it doesn't
have anti-lock brakes...

The aggravating part is that after searching over the entire transmission,
top to bottom, I can't find damage anywhere, just dirt.  No broken wires, no
dents, no scrapes.  Only single wire sensor looking part is what I
described.  It looks like it could be a magnetic pick-up, going into the
final drive, and yes, it's under the passenger side of the final drive
portion of the transmission.  The wire for it actually goes over the top of
the transmission and into a larger harness.  No visible means to disconnect
the wire when I pull the thing out...

Looks like a trip to the junker to try pulling the sensor out all the way
over there and see how the wire detaches.

There is a VSS in the dashboard also?  If that were the failing unit,
wouldn't the speedo still function?

Also forgot to mention, the transmission is flashing out a problem using the
'power' light on startup.  Anybody know the means to read those flashes,
which I would assume is similar to reading the CEL?

~Brian

Sounds like you have found the transmission VSS. Wire does not
disconnect at the sensor. Look where all those wires for the
transmission connect on the passenger side under the firewall. This
is where the VSS wire can be unplugged. 16 flashing lights is not
good. Flashing because something is seriously wrong with the
transmission. I found a file I had stored that shows the procedure
for pulling the transmission cods but can't paste it for some reason.
I have a Mac and the file is a pdf, whatever that is.

 

[Brian]

Sounds like you have found the transmission VSS. Wire does not
disconnect at the sensor. Look where all those wires for the
transmission connect on the passenger side under the firewall. This
is where the VSS wire can be unplugged. 16 flashing lights is not
good. Flashing because something is seriously wrong with the
transmission. I found a file I had stored that shows the procedure
for pulling the transmission cods but can't paste it for some reason.
I have a Mac and the file is a pdf, whatever that is.

PDF? Macintosh? It sounds like the document you have is in Adobe's
Acrobat format. I would love to get my hands on the document, if it has
codes and the procedure for retrieving them, but I feel I'm putting you out
if I ask you to email it. strchild-hotmail-com Either way, thanks for the
help so far. I will trace the wiring all the way back to the firewall.
From my vantage point yesterday, it looked as if the single lead became part
of a larger harness and became inseparable but maybe not... Seems rather
obnoxious, but it is what it is. I'm actually assuming the transmission is
beeping out something because of the VSS, but who knows. It likes to flash
at me if my engine stalls out at a stop, also, but after a restart it's
happy. My all-wheel-drive still works, and the tranny still shifts through
the whole range, and pretty much feels the same as before the VSS failed,
except I can't tell if my lock-up clutch is working. I don't know when I
hit 55 so it's hard to watch for that small 250 RPM drop on the tac.

Would be nice if an online auto parts place had a picture of the part, so I
could tell if I had the right one or not, but sounds like I must be close.


~Brian

 

[Brian]

Went off the road the other day and the speedo stopped working. Check
engine light came on and is reporting a 33 which checks out to be the
Vehicle Speed Sensor or (VSS).

I've been through the group here and through Google, looking for the
location of the sensor but I can't find it. Best I've come up with is
somewhere on the front differential, but after throwing the car on ramps,
crawling all over and under the car, umm, can't find it anywhere. Closest
I've come to any sort of sensor on the tranny is a round, single wire unit
that is on the third portion of the transmission, just above where the
exhaust 'Y' comes together. It is being held in place by a single 10m
bolt, which after removing the bolt, I couldn't get the stupid sensor to
come out. I got it out most of the way, but the wire is too tight to come
out further and actually has no harness that can be disconnected. Hmm.
Also, the sensor seemed to have what looked like gear oil on it after the
partial removal, but only a bit, and nothing was leaking out around it.
Is this the VSS and I just haven't pulled hard enough to get it to
dislodge all the way?

I'm frustrated. I would like to fix the problem, but I don't know where
to look for the bugger.

The top of the tranny has the mechanical cable feeding from the
top-passenger side through the firewall to the back of the dash. I am
figuring if it were just a cable, how would the computer know, unless
there is a feedback from the dash, which I doubt. Sounds too
sophisticated for this car.

Would love help with this, if anybody knows.

Thanks!

~Brian

Yay! Came across this web page this morning:

http://autorepair.about.com/library/faqs/bl833h.htm

It shows the location of both speed sensors, and hopefully somebody else can
use the information too!

Turns out the part I found IS the VSS. Now to go to the junker and get
another one...

Thanks for the putting up with my ramblings, everybody.

~Brian

 

[bugalugs]

Thanks for the putting up with my ramblings, everybody.

~Brian

That's what we're here for.

 

[johninky]

Tried to email that doc. Don't know if I did, having never done this
before. Post if you receive it. Still think you are fixated on the
wrong VSS. One in the instrument panel is powered by the speedometer
cable which I think you stated quit working.

John

 

[Brian]

Tried to email that doc. Don't know if I did, having never done this
before. Post if you receive it. Still think you are fixated on the
wrong VSS. One in the instrument panel is powered by the speedometer
cable which I think you stated quit working.

John

Thanks John! I received the document from you and read through the
contents... The extension on it was ._pdf which after changing to .pdf was
able to open just fine - in case you are still having troubles with it. Not
sure how it works on a Mac.

Yes, the speedometer stopped working. Wonderful, so perhaps you're right!
I'm hoping querying the transmission will indicate which of the two speed
sensors has quit working, as both are listed under separate trouble codes.


It's late, and since the instructions say to to warm the engine and drive
above 12 MPH before retrieving codes I will try checking it at the gas
station later tonight to see if I can get the instructions to work.

The instructions mention "Move select lever to "D" and connect diagnosis
switch to ON.***" - I assume they mean the black wire under the dash that is
part of the black / green combo for checking regular codes on older Subes?
I guess I will find out if that works or not. Any idea what other diagnosis
switch the manual could be referring to?

Either way, seems a very convoluted procedure for checking codes compared
with that of the engine:

.. Warm-up engine
.. Turn ignition switch off
.. Turn ignition switch on
.. Check if indicator light comes ON
.. Drive vehicle faster than 12 MPH (20 km/h)
.. Stop vehicle at ignition switch OFF
.. Move select lever to "D" and connect diagnosis switch to ON.***
.. Turn ignition switch on
.. Move select lever to "3"
.. Move select lever to "2"
.. Move select lever to "1"
.. Partially depress accelerator pedal
.. Ensure indicator light blinks

- 4-HZ blinking indicates a faulty battery
- 2-HZ blinking indicates Normal
- any other blinking will be trouble codes, read like the engine trouble
codes
- steady - check inhibitor switch, diagnosis switch, wiring, TCM, etc.

11 - Duty solenoid A
Detects open or shorted drive circuit, as well as valve seizure.

12 - Duty solenoid B
Detects open or shorted drive circuit, as well as valve seizure.

13 - Shift solenoid 3
Detects open or shorted drive circuit, as well as valve seizure.

14 - Shift solenoid 2
Detects open or shorted drive circuit, as well as valve seizure.

15 - Shift solenoid 1
Detects open or shorted drive circuit, as well as valve seizure.

21 - ATF temperature sensor
Detects open or shorted input signal circuit.

22 - Mass air flow signal
Detects open or shorted input signal circuit.

23 - Engine speed signal
Detects open or shorted input signal circuit.

24 - Duty solenoid C
Detects open or shorted drive circuit, as well as valve seizure.

25 - Torque control signal
Detects open or shorted input signal circuit.

31 - Throttle position sensor
Detects open or shorted input signal circuit.

32 - Vehicle speed sensor 1
Detects open or shorted input signal circuit.

33 - Vehicle speed sensor 2
Detects open or shorted input signal circuit.

 

[Brian]

Went off the road the other day and the speedo stopped working. Check
engine light came on and is reporting a 33 which checks out to be the
Vehicle Speed Sensor or (VSS).

I've been through the group here and through Google, looking for the
location of the sensor but I can't find it. Best I've come up with is
somewhere on the front differential, but after throwing the car on ramps,
crawling all over and under the car, umm, can't find it anywhere. Closest
I've come to any sort of sensor on the tranny is a round, single wire unit
that is on the third portion of the transmission, just above where the
exhaust 'Y' comes together. It is being held in place by a single 10m
bolt, which after removing the bolt, I couldn't get the stupid sensor to
come out. I got it out most of the way, but the wire is too tight to come
out further and actually has no harness that can be disconnected. Hmm.
Also, the sensor seemed to have what looked like gear oil on it after the
partial removal, but only a bit, and nothing was leaking out around it.
Is this the VSS and I just haven't pulled hard enough to get it to
dislodge all the way?

I'm frustrated. I would like to fix the problem, but I don't know where
to look for the bugger.

The top of the tranny has the mechanical cable feeding from the
top-passenger side through the firewall to the back of the dash. I am
figuring if it were just a cable, how would the computer know, unless
there is a feedback from the dash, which I doubt. Sounds too
sophisticated for this car.

Would love help with this, if anybody knows.

Thanks!

~Brian

Final diagnosis: Defective speedometer cable.

 

[1 Lucky Texan]

Final diagnosis:  Defective speedometer cable.

Thanks for bumping the thread with the results!