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Tach input signals

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my speed info suddenly quit. Also the engine is not running stable at idle and the check engine light comes on. I think that is caused by the inop tach info. I assume fixing that also solves the other problems?

Could you please tell me, where the tach gets the info from so that I can check/repair the faulty sensor??




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my crystal ball is in the shop, you need to tell us which model, which engine, which trans, how many miles, what is it doing / not doing, and go to the parts store and have the codes read for free.





any activity? or just dead?


how long has it been doing it?

did it just start?

has it ever been ok?


is the car new to you?

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Sorry, you are right, the info is inaccurate and also wrong. It is the speedometer that suddenly quit working a week ago, just dead. (sorry english is not my first language).

Thereafter (minutes after) I realized the check engine light while driving as well as an unstable idle rpm. Other than that everything is fine (engine performance etc.)

I am driving the car since 4 years now, never had any problems. It is an 1998 Legacy 115HP, 2litres, 110000 miles.

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Thanks for info!

The thing is I have no chance (right now) to read out the code for the check engine light. Subaru is not very popular in Germany (where I am from) and even less in Spain (where I have based the car).

I assume that this light is connected to the faulty speedo instrument. Hence I think trying to repair the speedo removes the other problems (check engine light+unstable idle rpm).


To johnegg:


Where is the bad front speed sensor situated?? I have manual shifting.



To broknindarkagain:


Tks for your offer, I think I am quite fluently in English, however some special words are sometimes missing, so I mixed Speedometer and Tach Meter.

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not sure about the 5 speed trans.


look here: http://opposedforces.com/parts/legacy/en_b11/type_7/manual_transmission/mt_speedometer_gear/illustration_1/


it does not show the speed sensor, and i can't seem to locate it in the drawings, but the speed sensor screws into the trans on top of the speedo gear shaft in the diagram.


there should be a diagram on that site showing the speed sensor location, it is just a matter of looking in the right place.


NOTE: in the US on the 95 - 99 legacy, the speed sensor was moved from inside the speedo, cable driven, to a trans mounted unit which drives the speedo by an electrical signal. i assume / hope this info is the same for your car.


hope this helps.

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