How to diagnose a vehicle speed sensor VSS
03-15-2010, 07:44 PM
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How to diagnose a vehicle speed sensor VSS How can I diagnose if my speed sensor on the T56 is acting up? Not sure if this should go in the trans section since I am asking about the sensor....
My speedometer goes up to 20 and pretty much stops. I pulled the speedometer signal from the green wire with white strip on the white dash connector.
I checked DC voltage on the wire to my speedometer and at a stop with the car on its reading 12V Under 20 mph (by GPS) the voltage fluctuates between 2 and 9 volts. at ~60 mph the voltage holds steady around 6 volts....I thought the VSS was a 5 Volt sensor?
Any help is appreciated.
My speedometer goes up to 20 and pretty much stops. I pulled the speedometer signal from the green wire with white strip on the white dash connector.
I checked DC voltage on the wire to my speedometer and at a stop with the car on its reading 12V Under 20 mph (by GPS) the voltage fluctuates between 2 and 9 volts. at ~60 mph the voltage holds steady around 6 volts....I thought the VSS was a 5 Volt sensor?
Any help is appreciated.
Last edited by Berto; 03-15-2010 at 08:10 PM.
03-15-2010, 11:26 PM
#2
The VSS signal isn't handed to the speedo, it goes to the PCM. The best bet is use a real time scanner and see what the VSS shows in the PCM when you take a drive. You can't measure for it at the speedo without a scope; it's not a simple DC voltage AFAIK.
