i lose a gear when the check engine light comes on
my 1984 olds 98 has had some trouble when im on da highway. sometimes the check engine light comes on and it seems as though i lose a gear and my rpms increase. sometimes it will shut off and will upshift but sometimes it doesnt. it only does it in overdrive. the tranny is a thm200-4r. i know this tranny is not very good for the weight of the car because i have read about a lot of people that have had trouble with them. any help is appreciated.
why do you drive overdrive on the highway, just wondering
Because that's what overdrive's for...... Decreases ratio to about 0.75:1 to increase economy.
i know what overdrive is and what it does, i asked him why does he drive in overdrive if thats what causes his problems.
check the codes. A GM 4 speed THM has inputs to the ECM via the various relays in the tranny identifying which gear the car is in.
well right now i am getting 10 mpg if im lucky so i need all the help i can get. i am going to check for loose wiring. someone told me that it may be the torque converter coming unlocked so i gotta go through all the sensors and stuff. next time im out ill see how much of a gear reduction i lose, like if its a whole gears worth or not.