Speedometer working On and Off

[Ned]

2 Issues
1991 NSX, Manual Transmission, 154,000 miles
1) Yesterday after driving with cruise control on for one hour, the cruise shut off and speedometer dropped to zero. Over the next two hours, the needle would jump all around and occasionally land on the correct speed. It spend most of the time at zero and the cruise control would not work. Under hard braking, check engine light and traction control light would come on. If I turn the car off, these two light would go out.
After two hours speedometer and cruse control went back to normal and worked fine.

2) A/C fan speed control stops working after use but then after turning off for awhile works again. My guess is the A/C circuit board needs rebuilding.

Any thoughts on these two items?
Thank You

 

[synergy004]

Speed sensor symptoms

 

[scammy]

Correct VSS I think its called mine did it at the track and the engine would cut out at about 7000rpm, so you just need a new one. There was another thread about this not long ago, read this http://www.nsxprime.com/forum/showt...or-replacement?highlight=Vehicle+Speed+Sensor

 

[95nsxtc]

im gona sound really shady with this and im not positive on how our cars work with mileage buuuut, in some vehicles, if the speedo stops working, your car stops accumulating mileage on the odometer, so it may not b the worst problem....

found this out in an 07 exige s after a super charger build swap where the speedo would stop periodically...

 

[scammy]

im gona sound really shady with this and im not positive on how our cars work with mileage buuuut, in some vehicles, if the speedo stops working, your car stops accumulating mileage on the odometer, so it may not b the worst problem....

found this out in an 07 exige s after a super charger build swap where the speedo would stop periodically...

the car will not run to its full potential if you do not replace the VSS, the engine will cut out at 7000rpm or there abouts when the VSS gets hot, when it cools down you are good to go again with no cel codes but it will get worse so saving mileage with this issue is not a good thing

 

[95nsxtc]

Lol im not saying that im doing this, im saying there could b a slight benefit

 

[xxxdominion]

Had this exact problem on my 91 at around 94k miles. Order a speed sensor form rock auto, but scroll down the list to get the better quality items. should run you about 120-150$ and it takes 15 minutes to replace. Easy! AIRTEX / WELLS Part # 5S4594

 

[Mikexike]

78420-sl0-505 sensor assy., 0 sp $148.78 from factory

 

[nsxspdfreak]

2 Issues
1991 NSX, Manual Transmission, 154,000 miles
1) Yesterday after driving with cruise control on for one hour, the cruise shut off and speedometer dropped to zero. Over the next two hours, the needle would jump all around and occasionally land on the correct speed. It spend most of the time at zero and the cruise control would not work. Under hard braking, check engine light and traction control light would come on. If I turn the car off, these two light would go out.
After two hours speedometer and cruse control went back to normal and worked fine.

2) A/C fan speed control stops working after use but then after turning off for awhile works again. My guess is the A/C circuit board needs rebuilding.

Any thoughts on these two items?
Thank You

Just replaced mine. Faulty Speed Sensor will result in a inop speedometer and will activate the TCS
From AM Auto Parts http://www.am-autoparts.com/?utm_source=Follow_up&utm_medium=email&utm_campaign=Invoice_email

AM-10152457

Acura NSX Speed Sensor;Make: Acura / Model: NSX / Year: 1991

40.55

40.55

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- - - Updated - - -

2 Issues
1991 NSX, Manual Transmission, 154,000 miles
1) Yesterday after driving with cruise control on for one hour, the cruise shut off and speedometer dropped to zero. Over the next two hours, the needle would jump all around and occasionally land on the correct speed. It spend most of the time at zero and the cruise control would not work. Under hard braking, check engine light and traction control light would come on. If I turn the car off, these two light would go out.
After two hours speedometer and cruse control went back to normal and worked fine.

2) A/C fan speed control stops working after use but then after turning off for awhile works again. My guess is the A/C circuit board needs rebuilding.

Any thoughts on these two items?
Thank You

If you haven't replaced the VSS yet here is a thread where I posted some instructions on replacing it. It will take little longer than 15min, more like 45min.
http://www.nsxprime.com/forum/showthread.php/189114-speed-sensor-replacement?highlight=speed+sensor