2001 Toyota Corolla Werid Speedometer problem

2001 TOYOTA COROLLA
121,000 MILES • 4 CYL • FWD • AUTOMATIC
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EDTA1
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  • 3 POSTS
Hello All,

I press on the gas, and my speed is 0 (but I'm moving). I let go of the gas and let it coast, my speedometer comes alive again. I've checked the vehicle speed sensor (VSS) and it's not it. It generates about 12 volts 4 times per rev of the pinion. I'm getting about 12 volts from the harness as well. So it's not like its not getting voltage. I use an OBD reader and it corresponds to what the speedometer reads (fluctuating as mentioned). What's the problem here? Is there something that links the speedometer to engine revs? Please advise.
Apr 29, 2009 at 8:38 PM
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MMPRINCE4000
  • AUTOMOTIVE REPAIR CONTRIBUTOR
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VSS generates electrical output called pulses per mile. PCM converts to readable MPH, if VSS is OK then problem lies in wiring to speedometer or the speedometer gauge itself.

While possible the VSS is outputting voltage, the VSS gear mat be loose giving erratic readings.
Apr 30, 2009 at 5:22 AM
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EDTA1
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when you say vss gear, do you mean the pinoin that's on the end of it?
Apr 30, 2009 at 6:11 AM
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EDTA1
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Also, if the problem is in the guage, how do you fix that? Replace the guage? Is there a quick test to test if the guage is good or not?
Apr 30, 2009 at 6:12 AM
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MMPRINCE4000
  • AUTOMOTIVE REPAIR CONTRIBUTOR
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Make sure pinion is seated fully. Dealer or trusted garage can test speedomter gauge.

They can also test VSS output. If you have a scan tool you can read VSS output in live data mode.
Apr 30, 2009 at 6:49 AM