Speedometer Acting-up. Help..

[nimdivino]

Hey guys, my speedometer is intermittently acting-up. There would a day where it works the whole time, then some days it will just drop to 0 mph, then about half-a-mile later it starts to work. Sometimes it will even go up and down like a madman.

Is it the Speed-sensor?? And has anybody replaced the sensor? Looking at the manual, the speed-sensor is located by the tranny, are there more speed-sensors in the car that I should know about? Maybe behind the cluster? And is it hard to replace?

Thank you very much.

niM

 

[drew]

Is it the Speed-sensor?? And has anybody replaced the sensor? Looking at the manual, the speed-sensor is located by the tranny,

Yes: the speed sensor

Yes: I have replaced one

Yes: the one on the tranny

No: It is easy to replace. Takes only a few minutes and a wrench

Drew

 

[Larry Bastanza]

What year car?

Which transmission type?

LarryB

 

[nimdivino]

ah sweet.. thank you very much..

The car is a 91 NSX.

niM

 

[Larry Bastanza]

If the trans is manual, what Drew said.

Regards,
LarryB

 

[Briank]

Normally speed sensor problems also cause ALB and TCS issues. I would check if the connectors to the gauge cluster are connected properly.

 

[Batmobl]

the exact same thing happened to me. you need a new VSS vehicle speed sensor. I dont know if you work on your own car but its super easy to do yourself. The part is like 60 bucks.

 

[nimdivino]

hey guys, thanks again for the help.

quick question, what is ALB??

niM

 

[nimdivino]

hey guys, thanks again for the help.

quick question, what is ALB??

niM

 

[Larry Bastanza]

Anti-Lock Brakes

 

[nimdivino]

aaaaaaah....

Thank you again guys for the help.

niM

 

[cannik]

Just wonder how much will be the fixed?
I want to the the failure of the sensor will cause speedometer drops or swing like mad and the TCS & Check Engine light both come out???? Please advise.

 

[nimdivino]

Just wonder how much will be the fixed?
I want to the the failure of the sensor will cause speedometer drops or swing like mad and the TCS & Check Engine light both come out???? Please advise.

The broken speedometer sensor will cause speedometer to drop or swing, but it shouldn't turn the TCS and check engine light on.

THis has happened to me once before though, and what I remembered is that I heeled-toe rather poorly which made the vehicle looses its balance a little bit before I took a turn.

From the explanation here:
http://www.nsxprime.com/forums/showthread.php?t=37673

I basically "tripped" a wire and that set off both lights. There is nothing wrong with your car, and I doubt it will happen again anytime soon.

Oh another thing, sometimes my TCS light will come-off, and this is ONLY when the road is pretty rough.

niM

 

[drew]

The broken speedometer sensor will cause speedometer to drop or swing, but it shouldn't turn the TCS and check engine light on.

actually it does cause the lights....the VSS is an input for the TCS.

**

I'm not sure how to answer "what does it cost"? Replacing the VSS takes 10 minutes, one wrench and the only preparatory work is to open the engine hatch.

I suppose the dealer could charge several hundred dollars for the labor too. They might even try to stick you for a "complete analysis" and other fear mongering at huge cost too.

 

[nimdivino]

That actually makes a lot of sense.. If I was driving, then all of a sudden my speedometer drops to zero, then swings back to the right speed, and does this 3-4 times, the TCS light will turn-on? This is definitely not the case on my car though, because the speedometer swings happens to me frequently but the TCS never lights up.

niM

 

[dx3]

Guys,

Ran into this problem today. My speedometer dropped to ZERO and then my CEL and TCS lights came on. I stopped and turned off the car, turned it back on and the lights had gone out and the speedometer started working. 30 mins later the same thing happened.

Does anyone have a DIY on replacing the VSS(91 manual)? Also, where is the cheapest place to find the part?

Didn't mean to take over your thread but didn't see the need to start a new thread about the same problem.

Thanks,
Jonny

 

[Honcho]

Ressurecting this thread based on my drive at NSX Stock 2010. Near the end of the run, the speedo started jumping up and down and then died. It came back a few minutes later and was working fine. On the way back to long island, it started jumping again and died again about 10 min from my house. A quick chat with LarryB suggested the speed sensor, but my TCS and CEL lights never came on. I am going to check and clean the connections.

The speedo has never acted up before and this last run was the longest and hardest I've ever driven the NSX by far. Lots of high-rpm bursts followed by sitting idle and heat-soaking over and over. Do you think it could just be excess heat affecting the sending unit and/or wires? Is it worth wrapping the wires and unit in heat-reflecting tape?

 

[Briank]

If you are not having TCS and ALB issues then its most likelly not the speed sensor. Check and reseat the connectors to the gauge cluster.

 

[Honcho]

Thanks Brian, I'll try that. Is it possible for the sensor to go bad without tripping the TCS/ALB lights?

 

[FelonyRuckus]

Honcho,

Neither of my ABS or TCS lights came on and it was definitely the speed sensor 1aauto.com has them for about $36 I haven't had a problem since

 

[Honcho]

FelonyRuckus-

I think you are right. I just looked through the TCS circuit diagram and the Speed Sensor is not an input. The TCS gets its wheel speed data from the four wheel speed sensors at the hubs (shared with the ALB system).

 

[Larry Bastanza]

A quick chat with LarryB suggested the speed sensor, but my TCS and CEL lights never came on.

Bad VSS, that's my story and I am sticking to it.

78420-SL0-505

Regards,
LarryB

 

[Honcho]

Bad VSS, that's my story and I am sticking to it.

78420-SL0-505

Regards,
LarryB

The master has spoken.

 

[ralph cerbone]

go with what Larry B says,i dont have a 91 manual ,but do have a 97 manual which shows VSS as a input to TCS , you have to understand reading a repair manual is NOT like reading a novel ,one chapter does not always flow into the next ,some manufactures call this inclusive logic. they dont teach this this to their techs :example , ABS turns on at 7mph and monitors wheel speed for potential lock up , Question is when does ABS turn off , What happens if it doesn"t , Answer : it is off up too 6 mph if it doesn"t turn off you will not stop your car ,think about it ! i fabricated a VSS sensor and feed inaccurate info to ECM on a ABS car , got car not to stop , we all learned something that night :wink:

 

[FeetFxr]

Anyone know where I could try to get one of these speed sensors?

My '92 just started doing all this stuff with the speedo all over the place and TCS light coming on. I took it in to "the shop" and they are saying there is only one VSS available in the country right now and it's in California. Parts and labor are supposed to be $200-300. This sounds like it should be a fairly cheap & easy DIY from what I'm reading.