I have a 2000 Blazed 166k v6 and yesterday i was driving on hwy on cruise control then all of a sudden RPM's go from 1900 to 2600 and check engine light came on. all other gears work fine 1 2 3 r p all work. But when i get on Hwy it wont go into the last gear. I am taking it to get codes read today but wanted to know if anyone knows what this might be before i go and get this done. Trans fluid is good and red.
Thank you in advance
C

 

There is no 5th gear in the automatic transmissions. Do you mean 4th?

 

HAHA YES THE LAST GEAR IT GOES IN when i am going 70 i am close to 3000 rpm's

 

wow nice forum i need help and no one helps! its an automatic

 

We have lives too... Patience is a virtue!

The troubleshooting chart for no 4th gear or slips in 4th states a mis-placed check ball or an improperly installed orifice plug. Since it doesn't appear that you have recently done any work on your transmission, I would say that you may have a worn separator plate that has allowed a check ball to drop through or leak excessively.

Here is a quote from HotRodders.com for a "no 4th gear" question:
I have also read that this could be caused by a bad 1-2 shift solenoid. This is an easy swap after dropping the pan unlike the other scenarios listed above.

Hope this helps. Next time, try not to direct your frustrations with your vehicle towards those that may be trying to help...

 

1-2 solenoid is gunna be first try i wil also try 3-4 since i will be in there. i hope this works. thanks