1999 Mercury Cougar nor sure if electrical or transmission

Tiny
SPETEE
  • MEMBER
  • 1999 MERCURY COUGAR
  • 6 CYL
  • AWD
  • AUTOMATIC
  • 115,000 MILES
I was driving on the interstate going about 70 and my speedometer spiked all the up and then went to zero. It stopped working. RPM gauge runs good and the rest of the instruments are working no problem. When this happened I felt something vibrate on the gas pedal when I accelerate. The next day I noticed it was shifting hard when it changed gears and now it won't change out of gear after 35-40MPH.
I recently had my oil changed and fluids topped off and they mentionied my transmission fluid was dirty looking but nothing else. I also had new tires put on at the same time.
Just not sure if this is transmission related or electrical. Any help in the right direction would be greatly appreciated.
thanks
sabrina
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Thursday, September 17th, 2009 AT 4:04 PM

11 Replies

Tiny
RACEFAN966
  • EXPERT
Ok it sounds like you had you Vehicle Speed Sensor (VSS) go bad. This sensor runs the speedo and also helps with shifting. If you have a digital mutli meter then I can walk you through a test on it and make sure it is bad. Let me know what you want to do. Thanks.
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Friday, September 18th, 2009 AT 10:10 AM
Tiny
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Hi,
I have the regular speedometer and then I do have a digital display that can show my MPG, Miles till empty, rate of speed, and something else. Is this what you are referring to?
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Friday, September 18th, 2009 AT 12:37 PM
Tiny
RACEFAN966
  • EXPERT
No there is a vss on your car sense about 95 Ford hasn't put a speedo cable on most of their cars and trucks. Even though there isn't a digital readout it is electrically run by the vss, and like I said this also helps with shift points. So I need to know if you have a digital multi meter that we can test the VSS with? The VSS is on the rear end near the center from the drivers side here is a pic of the sensor I would like to test.


http://www.2carpros.com/forum/automotive_pictures/249564_551041_1.jpg

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Saturday, September 19th, 2009 AT 8:52 AM
Tiny
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Yes I have a digital multi meter and I pulled off the VSS yesterday. My car has 2, one in the front and one in the rear but I pulled the one in the rear. What should my read out be.
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Saturday, September 19th, 2009 AT 8:58 AM
Tiny
RACEFAN966
  • EXPERT
Sorry I forgot your car is Front wheel drive so it will be on the trans not in the rear. You only have one VSS but you do have abs so you have wheel speed sensors too but those are needed to be tested on the VSS. I have included a pic of the plug of the VSS so follow that for test ok. Here is what to do. First check for power between the PPWR and PWR Ground shoud be 10.5 volts or more. If that is good then for voltage between pin 58 and 103 if more then 1 volt then there is short in the wiring, if less then 1 volt then here is the next step. Now measure resistance between pin 58 and 103 should read 3000 ohms. If all this test fine then replace sensor. Now you are doing these tests on the wire harness not the sensor itself.
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Saturday, September 19th, 2009 AT 9:14 AM
Tiny
SPETEE
  • MEMBER
Thanks for the info. I am having trouble locating the sensor. I removed the wheel on the front passanger and see a wire that looks like something should be pluged into it but the sensor doesn't fit. I looked by the drivers side and see the wire harness but can't find the sensor. I have a book but it isn't showing me exactly where to look for the sensor. Can you guide me to it please.
Thanks
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Tuesday, September 22nd, 2009 AT 8:42 PM
Tiny
RACEFAN966
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Ok it is on the transmission as you already know. It is on the right side of the transmission near where the case splits it will be best found from underneath.
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Wednesday, September 23rd, 2009 AT 9:22 AM
Tiny
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I had to take it to someone. I had the wrong VSS. I had the one in your picture but its not the correct one. Thanks for you help
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Wednesday, September 23rd, 2009 AT 9:56 AM
Tiny
RACEFAN966
  • EXPERT
Strange that is the one they showed for it sorry about that. Let me know how it works when your done.
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Wednesday, September 23rd, 2009 AT 10:05 AM
Tiny
SPETEE
  • MEMBER
Hi there,
The mechanic replaced the VSS and my car is running great. Thanks so much for your help and I will definately use your service again and make a bigger donation next time.

Thanks
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Thursday, September 24th, 2009 AT 1:09 PM
Tiny
RACEFAN966
  • EXPERT
Great glad to hear it is fixed and running good. Thanks for you support and it you have any other questions just ask.
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Friday, September 25th, 2009 AT 9:07 AM

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