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VSS replacement

rowekmr

New member
I am a new owner of a 02 Regal GS and the seller told me when the HD trans blew he replaced it with a 02 LS transmission with a HD differential. It hasn't been driven that much because it had front suspension problems but the trans shifts funny sometimes and the SES light is on. While getting new struts the mech pulled the codes and said I had one for the VSS. Where is the VSS located? If I need to replace it (it might be disconnected) should I replace it with a HD VSS or a n/a VSS or are they the same?

Thanks
 


Agreed. You need to have the PCM tuned for the proper gear ratio. The original HD trans came with 2.93 gear ratio and the replacement transmission has a 3.29 gear ratio. Your two options are taking apart the transmission to put the proper gear ratio in or to have it tuned in the pcm to the current gear ratio.
In the diagram below you'd need to change that piece to a 34 tooth VSS reluctor wheel.
TransDiagram_zps1d535d44.jpg
 
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The seller said it was tuned before he sold it via a handheld tuner. Once I verify the VSS operation I was planning on looking into whether it was tuned or not. What are the symptons of a 3.29 trans that isn't tuned?
 
Typically it will cause max line pressure during shifts and cause harsh shifts. There have been occasions where the VSS reluctor wheel has not been pressed on all the way and has caused the sensor to no pick up a very good signal causing it to throw codes.

It's tricky but you could check by taking out the VSS sensor and using a mirror to look and see if the reluctor wheel is fully seated onto the differentail.
 


Where is the VSS?
Typically it will cause max line pressure during shifts and cause harsh shifts. There have been occasions where the VSS reluctor wheel has not been pressed on all the way and has caused the sensor to no pick up a very good signal causing it to throw codes.

It's tricky but you could check by taking out the VSS sensor and using a mirror to look and see if the reluctor wheel is fully seated onto the differentail.
 
TransDiagram2_zps02488017.jpg


Here is a view of the back side of the transmission the is right up next to the firewall. The VSS Vehicle Speed Sensor is on the passenger side of the transmission near where the axle goes into the transmission.
 
Three things I've found to cause a VSS error:
1. The dope forgot to plug it in. If this is the case, smile...it's your lucky day
2. VSS sensor itself. Not so bad to replace, 10mm bolt on the far side of teh sensor holds it down. Wiggle and lift up.
3. Loose reluctor wheel. While it's not common, it happens. Sometimes a trans heats enough and the wheel comes free. If so, pull the axle, pull the diff to engine bracket, VSS connector, other two bolts holding cover on and press the reluctor on better.
 
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