# broken speedometer



## jza80king (Oct 22, 2002)

Hey guys I have noticed that my speedometer is either broken or making a false contact of some sort. Sometimes it will read correctly and then suddenly it will jump up to 80 or 100 mph than it goes down to 20 mph than back up. It pretty much flucuates up and down and rarely reads correctly. I have searched and haven't had much luck. Someone told me that the speedometer gets the read from the transmission? Anyways, I pretty much drive around not knowing how fast I am going and it is annoying as hell watching my speedometer go up and down. Anyone know how I can fix this problem?


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## 2Fass240us (Aug 2, 2004)

jza80king said:


> Someone told me that the speedometer gets the read from the transmission? Anyways, I pretty much drive around not knowing how fast I am going and it is annoying as hell watching my speedometer go up and down. Anyone know how I can fix this problem?


S-chassis cars take the speed from the speed sensor, which is indeed on the transmission.

Do you have a tach? If so, you could use that to approximate speed (assuming you know the wheel speed : engine speed corrolation) until you get the problem fixed.


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## Slydin240 (May 20, 2004)

Do a search on 240sx.org thats where I found out where to fix mine.


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## jza80king (Oct 22, 2002)

2Fass240us said:


> S-chassis cars take the speed from the speed sensor, which is indeed on the transmission.
> 
> Do you have a tach? If so, you could use that to approximate speed (assuming you know the wheel speed : engine speed corrolation) until you get the problem fixed.


I have a tachometer but I really can't correlate rpms to mph, if that is what you mean. I try to stay in a low rpm range and just go with the flow of traffic or just under the flow of traffic. Thanks for the tips though guys


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## kilty_0 (Aug 21, 2004)

i have a similar problem except mine stopped working i was told that the entire speed sensor and speedometer had to be replaced and i was told that it was goin to cost $500 just to take it out and put it back in nothing else


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## mille-16i (Jun 16, 2004)

Always check the codes code 14 is speed sensor circut sounds like you have a sensor gone hay wire. Ya gotta love electronic speedo's they give you milage when you back up :thumbup:


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## jza80king (Oct 22, 2002)

Also, I forgot to mention that my odometer doesn't work sometimes. A couple of weeks ago I got upto 275-285 miles on one tank and the other day it only read upto 49 and then stopped working. If that helps anyone help diagnose my problem.


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