Sons 96 blazer shifting improperly and speedometer reading 0mph.shifted to 4wd and back to 2wd and everything was ok . but had problems again next day and he tried same thing and it worked also. I suspect faulty or loose connections/sensor .I will go look at vss that Swartlkk has recommended in other posts.Am I on the right track ? if not please educate me on what I should look for thanks ps. may or may not be related abs light came on 2months ago(still on)cleaned sensors at wheel no help

 

Sounds like the VSS sensor. Could definitely be related to the ABS light. You'd need to get the codes read to know for sure.

 

I just had this happened to my blazer to its definatly your vehicle speed sencor on the tail shaft of the transmission or transfur case . My part number from advance is s8310 , and costs about 50 bucks . But better than rebuilding the transmission again . I say that because my boss and I just rebuilt the tranny and it was my first total tranny rebuild . the transmission works awesome now .

 

thanks for info / cleaned sensor yesterday and will wait for next occurrence . when I had it out i measure resistance @ 1.6 k ohms (1600).............. he just walked in and says it is screwed up again. I guess I will go buy one . I will measure new one's resistance and post its value for next person. unless somebody posts it here first

 

since i measured 1600 ohms i thought sensor was ok so I checked wiring @vcm and didnt read the 1600 .So I check the wiring which turn out to be ok recheck sensor and it was open. Went to advance cost $56 (new measured 1250 ohms) put it in an it ran ok . reset p0502 to clear check engine light . ABS light still on though I am hoping it clears after miles or cycles . I saw on other posts people asking what wrench to use on VSS mine I used a 1 inch crows foot. Thanks to all the help and excellent info in Swartllk P0502 explained .

 

havn same problem, changed vss still no speedo and not shifting right any thoughts?