89 gmc 2500 4x4 350

Ask our auto mechanics for help to all your GMC truck questions.
Post Reply
doublejippo
Posts: 1
Joined: Mon Jun 30, 2014 12:41 pm

89 gmc 2500 4x4 350

Unread post by doublejippo » Mon Jun 30, 2014 12:48 pm

the speedometer stops working and makes the transmission downshift, we replaced the vehicle speed sensor with no luck

 

User avatar
carriedi
Posts: 2280
Joined: Wed Apr 10, 2013 12:42 pm
Location: Oregon

Re: 89 gmc 2500 4x4 350

Unread post by carriedi » Mon Jun 30, 2014 5:45 pm

check out your instrument cluster. speed sensor sends info to the cluster and then it goes out to other computers. If the cluster turns off the pcm sees no speed reading

Post Reply