Speedometer sensor location

[99obw]

Quite easy. I think I posted the procedure. Let me take a look around and get back to you.

 

EDIT: Take a look here...

 

http://www.ultimatesubaru.org/forum/showthread.php?t=18679

[Rockman]

Thanks a bunch for the info! The dealership wants $52 for the VSS and $149 for the speedo head so getting an idea of which one it is could save at least 4 cases of beer.

[Phillip]

The speedo on my '99 OBW with Auto Trans also works intermittently. I tried the windshield wiper button trick you described with no effect.

 

I have had an intermittent speedometer on our 99 outback with auto tranny for quite a while. I have been too lazy to fix it.

 

Our cruise works regardless of whether the speedometer is working.

 

Please try something for me...When the speedometer quits working hit the front windshield wiper button several times very quickly. Does it come back on? Works almost every time on ours, which makes me think it is the speedometer head or a bad ground.

 

I think the sensor(s) are further back on the top of the tranny. I can look in the FSM and let you know if nobody else chimes in.

[corsair]

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I checked with a Subaru stealership who says that there is a sensor INSIDE the speedo head which receives impulses from the VSS (I have a 1999). This (the speedo head) is likely the problem rather than the cluster itself. Putting the OLD speedo head into another cluster will likely not solve the problem. What needs to be replaced is the speedo head. I have an ODBII scanner and can tell you that this speedo problem does NOT set an error code into memory (since I have read no error codes on my car). If you go to a stealership, they will charge you an arm & leg to replace the speedo head and will recalibrate the speedo accordingly.

 

I don't have an exploded diagram of the speedo cluster & head. Can you post a picture (JPG) of the back of your junkyard cluster with the head separated from the cluster?? Does the speedo head have any electronics or any electronic connections to the cluster??? If someone has a PDF with an exploded view of the cluster, can you post it for the rest of us ??? I have looked high and low for a paper manual for my 99 Legacy, but have only been able to get an update manual (about 2.5'' thick of looseleaf pages) but which has no diagrams of the instrument cluster.

===================================================

 

Problem solved. I replaced the speedo head for my 1999 Subaru Legacy sedan w/auto trans (Subaru part # 85020AC330) for $160 (over the couter from the dealer). Now my intermittent speedo problem is gone. All it takes is 45 minutes and a medium & short regular phillips screwdriver to complete this R & R. Note that the part number above really includes 2 pieces, the mechanical portion of the speedo (including the dial & pointer) and the integrated circuit board mounted on the back of the speedo connected by 8 free-standing electrical connector pins & 5 phillips screws. Since the part from the dealer includes both items, I will never know whether the trouble was caused (only) by the circuit board. The circuit board has ONLY a single wire input (green wire with yellow stripes) coming from the sensor on the transmission. For those who follow, it may be worth investigating whether this circuit board is sold separately (and at much less cost) from the mechanical portion of the speedo/trip odomoter. If anyone wants pictures, please post here with a good email address & I will email.

[luv2lean]

Add me to the list of 99 OBW owners with an intermittent speedo. Can any body tell me the proper procedure to test the circuit to determine if I need to replace the sensor on the tranny or the speedo head?

 

BTW the wiper tap thing doesnt work on mine.

 

Thanks

[corsair]

Add me to the list of 99 OBW owners with an intermittent speedo. Can any body tell me the proper procedure to test the circuit to determine if I need to replace the sensor on the tranny or the speedo head?

 

BTW the wiper tap thing doesnt work on mine.

 

Thanks

 

It's probably a 99% probability that the sending unit works just fine. I had the dealer do the diagnostic for me & he drove the car around on a test drive with his diagnostic equipment, noted that the speedo did not work, but that the sending unit on the trans was sending out a signal. I can tell you specifically that the circuit board on the back of the speedo gets ONLY ONE single input wire from the sending unit because there is only a single wire coming up to the back of the speedo head. This tells me that if you can remove the cable from the sending unit, attach a wire with the appropriate connector, and run it into the inside of the car to an analog meter, you should see input pulses when you drive. Since the car is too new to have the dealer factory service manuals circulating freely, there no other way that I can know what type of signal is being sent from the sending unit unless you can engage a dealer mechanic to tell you a better way to diagnose it. Alrernatively, you might trace the sending unit wire color back thru the harness to try to get a better place to tap into the signal coming from the sending unit (which is located on the left side of the trans with a single wire coming from it). I know it's galling to say, but you might just save yourself the trouble and just buy the speedo and install it. Mine was installed with ONLY a short & medium #1 or #2 phillips screwdriver and 45 minutes of my time. It will take you way more than 45 minutes of diagnostic time & effort trying to continue to isolate it. IMHO... Just replace it.

[MiniTransAm]

Corsair,

 

How difficult a fix was this for you? Did the entire dash need to come out. I've got the same stupid problem and didn't if this was something I needed to devote a couple hours too or an entire day.

[luv2lean]

It's probably a 99% probability that the sending unit works just fine. I had the dealer do the diagnostic for me & he drove the car around on a test drive with his diagnostic equipment, noted that the speedo did not work, but that the sending unit on the trans was sending out a signal. I can tell you specifically that the circuit board on the back of the speedo gets ONLY ONE single input wire from the sending unit because there is only a single wire coming up to the back of the speedo head. This tells me that if you can remove the cable from the sending unit, attach a wire with the appropriate connector, and run it into the inside of the car to an analog meter, you should see input pulses when you drive. Since the car is too new to have the dealer factory service manuals circulating freely, there no other way that I can know what type of signal is being sent from the sending unit unless you can engage a dealer mechanic to tell you a better way to diagnose it. Alrernatively, you might trace the sending unit wire color back thru the harness to try to get a better place to tap into the signal coming from the sending unit (which is located on the left side of the trans with a single wire coming from it). I know it's galling to say, but you might just save yourself the trouble and just buy the speedo and install it. Mine was installed with ONLY a short & medium #1 or #2 phillips screwdriver and 45 minutes of my time. It will take you way more than 45 minutes of diagnostic time & effort trying to continue to isolate it. IMHO... Just replace it.

 

Thanks for the feedback. After my initial post and further research on this board i came to the conclusion that since i had no other warning lights or symptoms associated with the sending unit and the track record of the 99 OB speedos I would replace the speedo head. Got it today and The bad news - the new speedo from 1stsubaru.com is defective - does not work at all and verified defective by a speedo shop test. I'm sending it back for another, to be continued...

[itzik93]

rumlow,

 

I'm sorry this won't help you directly but it is topic thread related. To help anyone with a newer Sube with an auto, I've attached a pic showing it's VSS (vehicle speed sensor) location, passenger side just forward of the diff dip stick (somewhat hidden under the white connector in the pic). It has a 2-wire connector. I've placed the old VSS in front of the new installed one to show what it looks like. Not sure if all model years later than mine will be the same - 96 OBW/auto 2.5

 

In my case, the bad VSS was causing the speedo needle to jump wildly when below 30mph, then would act normal above 30mph. Also affected the tranny's shifts. Other speedometer problems could be caused by another VSS that's located in the speedometer head itself - a buffer circuit that the ECU uses. Fortunately, my problem was the cheaper and easier fix of the 2 VSS's.

 

Hope this helps someone else.

 

Have the same problem. on hot days or after a 15-20 minutes of driving, the speedo needle jump wildly between 0-30Mph (somtimes less), above that everything is OK. the odometer also doesnt work when the needle quits.

Tapped the cluster when it happend did not help. seems that the problem is the VSS on the transmission (which i already disassembled and pictured).

btw: its a 96' legacy (sedan) 2.0L FWD automatic.

 

[subaruVWnut]

Just purchased a 99 OBW and it also has the intermittent speedo problem. Odometer works, no chk engine light, so, from reading this thread it appears to be the speedo head. Taping on the windshield wiper stalk made it work again the last time it failed.

 

Hate to spend $160 for a whole new speedo head when this seems like an electrical problem. I'm pretty good mechanically, but not so good with electronics.

 

I'm intrigued by this relationship between the wiper stalk and the speedo which indicates some kind of electrical failure....has anyone explored this....perhaps a bad ground ???

 

Has anyone determined if the circuit board in the speedo can be purchased seperately??

 

Warren C.

[99obw]

Just purchased a 99 OBW and it also has the intermittent speedo problem. Odometer works, no chk engine light, so, from reading this thread it appears to be the speedo head. Taping on the windshield wiper stalk made it work again the last time it failed.

 

Hate to spend $160 for a whole new speedo head when this seems like an electrical problem. I'm pretty good mechanically, but not so good with electronics.

 

I'm intrigued by this relationship between the wiper stalk and the speedo which indicates some kind of electrical failure....has anyone explored this....perhaps a bad ground ???

 

Has anyone determined if the circuit board in the speedo can be purchased seperately??

 

Warren C.

 

http://www.1stsubaruparts.com will be one of the least expensive places to get the part, that's where I got it.

 

A bad ground is a possibility, but the bad ground would likely be on the speedo head somewhere as replacing it seems to cure it 100%. Perhaps something in the original design or construction made it reset when the washer pump either raised the ground (ground bounce) or lowered the +12V (supply droop) due to the current transient when the motor started. Intermittent symptoms are by far the hardest to find the cause of.

 

I'm not aware of a source for just the board, though you might be able to swap a used head from another year, I don't know for sure.

 

I'm an electrical engineer, and I guess I was just too lazy to take a look at it. I have little interest in debugging a board I don't have a schematic for, and after designing and debugging all day long I'm short on patience for electronics when I get home.

 

Swapping a new head is certainly an easily solution, though possibly not the least expensive approach.

 

Best of luck. Keep us posted if you find anything.

[jkrepps]

My '99 O/B manual tranny is having intermittent problems at ~150k. I'd asked on another Subie board about it and was told to replace the VSS. It's cheap enough but darned near impossible to get at!

Unfortunately, I managed to pop off the top of the old sensor but not get it out. At this moment, it's at a local garage that specializes in Subarus. Unfortunately, the chief mechanic didn't know how to get it out. Even Vise Grips slide off the plastic sides. He called the area Subaru dealership and their advice...get this...was to break it out!

I really haven't had many problems despite averaging over 500 miles/week but I'm really ticked at Subaru for making something that's incredibly hard to get out. Maybe a 'strap wrench' from Sears would do the trick. Bottom line, before attempting to replace the VSS sensor, make sure you can get the old one out first!

BTW, having just read all the posts to this thread, it sure looks like my problem wasn't the VSS. My 'work-arounds' consist of; 1) turning the ignition off & on even when in motion (nice to have a manual tranny but don't do it at night), 2) turning AC on & off and, once, 3) turning the cruise on & off. I didn't have any luck with the washer/wiper wiggle. I'll try fooling with the dashboard electrical connections if the new VSS doesn't work. I'll try to post a followup. Later today when I pick it up, I have to load 500lbs. of books into it for deliveries.

Has anyone fooled with the ignition switch? The reason I ask is that is definitely my #1 'fix', even though it doesn't work all the time. At 150,000 miles which includes many stops for delivery and photography, I'm wondering if there's something in the switch (or maybe a relay??) that tells the speedometer head to do its' thing.

[pgwilli]

Thanks for all the information.

 

After 4-5 years of living with my 99OBW's intermitent speedo, I finally used the advice from this thread and replaced the speedo head.

It only took about 30 minutes - I don't know why I waited so long.I guess one reason is I intend to drive the doors off this car and never sell it.

 

I do wonder what the actual mileage is on my car tho'. The odometer I just replced read 123,487mile, but I'm sure its a lot more than that

Is there any way to retrieve it from the ECU or ??

 

Thanks again to all the contributors here,

Paul

[deyoungc]

Many of you have provided great information, hopefully leading me to believe that I too need to replace the speedo head in my 99 OBW. I have just shy of 80K and recently replaced my original battery (I know, I probably waited too long!). Since it happened just after replacing it (within 200 miles), and the speedo failure might be an electrical issue...any ideas of possible connections between these two events?

[unibrook]

My 1989 Saab 9000 Turbo became erratic when I first bought the car used in 2000. It was shaky---intermittent from 0-25 mph for about a year, then it stopped working altogether for the next 2 years. The cruise control and odometer would not function when the speedo was not working. Then, one day.......it fixed itself. Worked perfectly thereafter. I assumed the problem was in the speedo head sensor. But I never dug to test/play/replace anything in there.

[a97obw]

A few weeks ago I changed the transmission oil in my 5 speed 97 Legacy OBW over to synthetic with the Valvoline SynPower stuff. About 2 weeks after that, and right after resetting the trip odometer after a refuel, my speedometer started acting up. Bouncing all around at any speed, the regular odometer as well as the trip were indicating erroneous mileage vs. mileposts on the interstate; at first it was about 50% of the distance traveled, then when the speedometer finally quit I got the CEL and the code was for the VSS.

So the speedometer and the odometer are dead, no amount of whapping the dash or fiddling with the stalks will bring them back to life. Figuring it is in fact the VSS, I had the local dealer order one for me, and here is what should be the correct part. Hope to install it today, will report back whether it fixed the problem or not.

 

Again, 97 Legacy Outback wagon, 5 speed manual at 91k miles.

 

 

 

 

 

 

 

 

 

 

 

 

<img src="http://i4.photobucket.com/albums/y141/Huffmeister/IMG_0538.jpg" alt="Image hosted by Photobucket.com">

 

 

 

EDIT: I now have a WORKING speedometer and odometer! Remove/replace took all of about 15 minutes total. The trick is to use a 17mm (across the flats) open end wrench with very small ends to enable you to actually turn the sensor in getting it in/out. Not much room against the transmission case.

When I removed the original one, I noticed that down in "the hole" and around the slotted drive, this area is BONE DRY. I can't see where any type of lubrication is going on with this thing. I put just a dab of grease on the tab of the new one and a light smearing of grease around the shoulder before installing. Access was from the top once I removed the snorkulus air box stuff. Took a few pics, will get them up in a bit.

[luv2lean]

I still have a intermittent working speedometer on my 99 obw. When the speedo quits, the odo quits, but the cruise still works. The wiper tap does nothing to help

 

A few months ago i ordered a new speedo head and installed it, but it did not fix the problem. I took the new speedo head to a local speedo shop where it was bench tested and determined to be defective. I sent it back to the subsaru dealer and got another new speedo head and installed it but got the same results. Now I'm thinking the speedo shop that tested the first new head didnt know what they were doing - even though speedos is all they do. Perhaps there was nothing wrong with the new speedo head and I have another problem - like the sensor. It just seems too unlikely that I got 2 defective new speedo heads.

Anybody see a solution here? If the sensor is bad would my cruise still work?

Thanks

[corsair]

I still have a intermittent working speedometer on my 99 obw. When the speedo quits, the odo quits, but the cruise still works. The wiper tap does nothing to help

 

A few months ago i ordered a new speedo head and installed it, but it did not fix the problem. I took the new speedo head to a local speedo shop where it was bench tested and determined to be defective. I sent it back to the subsaru dealer and got another new speedo head and installed it but got the same results. Now I'm thinking the speedo shop that tested the first new head didnt know what they were doing - even though speedos is all they do. Perhaps there was nothing wrong with the new speedo head and I have another problem - like the sensor. It just seems too unlikely that I got 2 defective new speedo heads.

Anybody see a solution here? If the sensor is bad would my cruise still work?

Thanks

 

I can't believe that you received two dead (new) speedos. The speedo that I ordered had two parts that come together: 1. the speedo face & 2. the circuit board that is connected to the back of the speedo face. Assuming that you didn't separate those items and use the old circuit board, I would have to guess that the next thing to check would be the sensor input for the speedo. I had the Subaru stealership take my car on a test drive with his diagnostic scanner who told me that he was able to see sensor inputs going to the speedo, so I bought the speedo head which cured the problem. I don't know how to advise you to determine whether you are getting sensor input pulses without having the stealership do it for you (because I don't own a factory service manual). Maybe you need to take your new speedo AND old speedo to a different speedo shop.

[luv2lean]

I can't believe that you received two dead (new) speedos. The speedo that I ordered had two parts that come together: 1. the speedo face & 2. the circuit board that is connected to the back of the speedo face. Assuming that you didn't separate those items and use the old circuit board, I would have to guess that the next thing to check would be the sensor input for the speedo. I had the Subaru stealership take my car on a test drive with his diagnostic scanner who told me that he was able to see sensor inputs going to the speedo, so I bought the speedo head which cured the problem. I don't know how to advise you to determine whether you are getting sensor input pulses without having the stealership do it for you (because I don't own a factory service manual). Maybe you need to take your new speedo AND old speedo to a different speedo shop.

 

Corsair - thanks for the reply. No, I didnt use the old circuit board. Speedo shops are few and far between. Just happened to have this one in my area, although they only fix mechanical speedos and not electronic speedos.

I also tried to test for sensor output by driving the car with a meter hooked up to difference spots on the back of the speedo to see if I got any reading, but got none.

I would probably just buy a sensor and install it, but I recall somebody saying the cruise control wouldnt work and a warning light would appear if the sensor was bad - neither of which is my case. Does anybody know if this is true?

Thanks