I have had a tough time getting this truck to lock up the converter. Ive finally come to check the vss and its curcuits. everything check out exept for the vss signal wire, I have a groung to the pcm, an 8 volt reference on the orange wire but, I have 5 volts on the white and orange signal wire gonig back to the pcm. I cut the wire at the pcm and there is 5 volts coming out of the pcm. in my mind that should not be right. any thoughts or help would be great.

 

do you have a friends truck that has same trans that you cud test? put your pcm in his truck and see if it acts the same?

 

no I wish I did!

 

For an accurate test you would need an oscilloscope to see if the signal coming out of the VSS is stable or erratic. IIRC if the pcm thinks the VSS is changing too fast it will disable it and cause all kinds of issues.

 

ok. thanks I'll see if I can get a scope.

 

IF you can then you might see if the signal coming out is consistent with the two notches in the balancer that triggers it.. you should see a square signal coming back to the pcm.

 

balancer? are talking abouty the same thing? I have a tach signal I was tal.king about the vehicle speed sensor. but I put a new one and a pig tail and connector on. Still nom lock up. everything seems to be right, I have a new pcm on the eway. thanks

 

just for kicks and giggles double check ur trans fluid level as well. sometimes the stupid stuff eludes us

 

Sorry, I was meaning the notches in the VSS wheel. I don't remember the number of teeth per revolution. I had another post on the brain. [duhh] The gear may also be slipping but that would be on the end of the tail shaft. I had that issue with my 2wd trucks.

 

well my wifes uncle brought his nice scope over and we checked the vss and the tach signal, they were real good then thought I didnt hook up the brake light switch to the pcm and It works! so I hope this will help someone else. thanks for all the help.

 

Wasn't much help talking one thing meaning another.

Glad you got it fixed.