1997 Lagacy Outback Wagon Automatic
My speedometer quit working and I am not quite sure what to look for. My Haynes manual makes some limited mentions of sensors 1 and 2. I know at least one of the sensors has to go though the ECU to get to the speedo. The locations of these sensors is not very clear. All the other guages are working fine. Any suggestions on how I could test to find out which part of the speedometer system is not working, without replacing everything to fix the problem. Or what part of the system might be at fault.
I do most of the work on my own car, so as each problem crops up, I try to learn what I can to eliminate it.

Richard

 

Richard,

It's most likely the speed sensor. Did your check engine light come on? And secondly, is it running in limp mode? ie: it won't rev passed 4k rpm. Honestly, I haven't had much experience with auto trannies, but have quite a bit with manuals. I have also seen the speedo gear break, unfortunately that's inside the tranny and requires a full teardown.

To determine if it's the speedo gear or the sensor, you need to remove the sensor. Unscrew it from the tranny, it's located on the passenger side. There will be a slot, you can see if it turns with a screw driver, it shouldn't. Also, put something in there, then roll the car forward or back to see if it turns, if so the speedo gear is ok. Then I probably just replace the sensor. On the older cars such as yours, the sensor feeds the speedo, then the speedo sends a signal to the ECU. On newer cars the sensor feeds everything directly.

Hope this helps,
Adam
alevy@i-speedusa.com

 

Adam,

Thanks for your help. I was looking in the wrong place for the sensor, anyway. I thought the sensor was located where the drive shaft goes into the back of the transaxle. That turns out to be a sensor for something else going to the ECU. I had already ordered a new sensor and it does not look like the one I was looking at. With your description, I found out where it really is located. I will see if this fixes the problem.

Richard

 

Adam,

Fixed it.

I will go into a little detail for Soobie owners interested.

First, I was looking at the wrong sensor (Vehicle Speed Sensor 1), located where the drive shaft goes into the back of the transmission. This one sends back info on the speed of the rear wheels in relation to the front wheels for transmission distribution.

Second, the speedo sensor (Vehicle Speed Sensor 2) is located on the passenger side (left hand drive) near the differential dip stick and can be reached from the top, leaning into the engine compartment.
This becomes easier to see the sensor, and the connector, and work on, once you remove the air intake duct between the MAF sensor and the throttle body. Removing and installing the sensor was quick and painless. Thanks to Adams reponse. Note that the Cruise control depends on this sensor and an engine warning light comes on when this sensor is not working.

Third, out of curiousity, I took the sensor apart and found the magnetic bearing had frozen up and rounded off the paddle that went into the transmission gearing. Fortuneatly, did not destroy the transmission gear.

Thanks again for your help Adam.

Richard

 

I forgot to mention. Adam suggested looking at the slot in the transmission, where the sensor goes, and moving the car to see if the slot move, rotates, therefore, testing to see if the gear is ok in the transmission. This would work just fine on a standard transmission, but you cannot activate the gear in an automatic transmission, nice idea, though.

Richard

 

Richard,

Glad to see that I could help. Yeah, the slot does move on the manuals, but wasn't too sure about the auto. Fortunately, it was only a sensor, like I said that I've had customers with a broken speedo gear. Specifically, the clip that retains the gear came/fell off, then the gear got mashed in the tranny. That sucks, to tear down a tranny for a little plastic gear that cost a few bucks.

Cheers,
Adam
alevy@i-speedusa.com

 

I have 1999 Outback 5-speed. The speedometer works about 90% of the time. 10% it just drops to zero and just sits until it feels like going back to the right speed. My cruise still works when it is at zero. No engine lights come on. Any thoughts?

Thanks.
Ben

 

Ben,

Sounds like it's the speedometer itself that is failing. If it was the sensor, there would be a code, then run in limp mode and the CC wouldn't work.

BTW; what motor? SOHC or DOHC

I haven't worked on any Outbacks so I would have to check diagrams to see what kind of speed sensor and wiring it has.

Let me know,
-Adam

 

I have a 2.5 liter DOHC. I did pull the wires off the speed sensor and took it for a test drive. The cruise did not work with the sensor disconnected but it still didn't give any error light on the dash. It's almost like there is a short circuit sometimes causing it to drop to zero.

Ben

 

I'd have to say that you're probably correct. Something inside the speedometer is shorting out. On DOHC motors, the speed sensor is a two wire (B + W). They go directly to the gauge cluster, then a seperate wire comes out of the back of the cluster and goes to the ECU & CC.

-Adam

 

We have 2 postal legacies, a 91 and a 97. The speedometer gears in the 4eat transmissions have worn out on both at around 130,000 miles. I differentiated the problem from a bad sender by inserting a Front-wheel-drive fuse and raising the front of the car. I started the cars and put them in drive and watched the slotted shaft with the cable adapter (91) and sensor (97) removed. When I removed the transmissions and the front differentials, the gears were not obviously damaged, but were perceptably smaller than the replacement parts. No way I could see to adjust out the wear. I think it would be theoretically possible for a contortionist with small hands to replace the parts on-vehicle by removing the axle-shaft bearing cover and bearing for access to the gears. The snapring on the driven gear would be hard to work... By the way, I had good luck with making a tool from a piece of 3" galvanized pipe, to remove the bearing cover.
Lee

 

this failing sensor thing must be common, as I just purchased a 1995 model (62,847 miles) with a failed sensor. dealer replaced it for free, no problems since.

 

Thanks for the info posted here. My '98 Forester just lost it's speedometer this morning - shortly thereafter the CEL came on. I'm hoping it's the sensor (i.e. not the gear and the subsequent teardown). Not a cheap part though at $112. Any suggestions for taking the dead sensor off? It appears to be threaded and have two flattened sides at its base - will a crecent wrench do for taking it out? And is it a normal thread (i.e. counter clockwise to loosen)?

Regards,

Craig

 

dogidaho, i had the same problem about 6 months ago, it was my sensor. i took it to a local repair shop and they did it in an hour, but i am not sure what tools they used

 

dogidaho,

The sensor has a normal thread CCW, and should come out with a 17mm wrench. Hope this helps.

-Adam