transmission problem

Hi! I have a 1995 blazer 4WD and I'm having some problems with my transsmision. When i start the truck and drive in D or OD for the first time the transmission shift from 1st to 4th but OD doesn't engage. that's the first problem, now when I brake and stop the transmission stuck on 3rd it does nopt downshift if i turn off the truck and start again it shift again from 1st to 4th but in the first stop it does the same thing.

by the way 4Hi and 4Lo don't engage neither.:frown:

Hi! I have a 1995 blazer 4WD and I'm having some problems with my transsmision. When i start the truck and drive in D or OD for the first time the transmission shift from 1st to 4th but OD doesn't engage. that's the first problem, now when I brake and stop the transmission stuck on 3rd it does nopt downshift if i turn off the truck and start again it shift again from 1st to 4th but in the first stop it does the same thing.

by the way 4Hi and 4Lo don't engage neither.:frown:

Welcome to AF on your first post.

Sounds like it is going into fail safe mode.

How many miles and what is the service history?
Fluid level and fluid condition?
Any check engine lights?
May be time to get a transmission capable scanner on it and see what is going on.
Post back any codes engine running or transmission.
MT

the blazer has 160 000 miles on it I just change oil and filter the first day works fine but the second day starts the fault actually if i gear in second and then back to D after i stop it shift from 2nd to 4th again but the next stop it does the same thing. what kind of scanner do I need to read the failure codes

the blazer has 160 000 miles on it I just change oil and filter the first day works fine but the second day starts the fault actually if i gear in second and then back to D after i stop it shift from 2nd to 4th again but the next stop it does the same thing. what kind of scanner do I need to read the failure codes

A good comerical type capable of reading both engine and transmission computers.
Good repair shop should be able to test it for you.
Obd11 scanners or code reader will not get a goob job done.
MT2500 snappie will do it with the right cartiage..
MT

Do you have reverse?

yes it has reverse but today when i try to drive i notice some slipping in shifts.

When has the fluid and filter been changed?

Any check engine lights?

I changed the oil and filter just one week ago

I changed the oil and filter just one week ago

TRANSMISSION FLUID and FILTER I meant.

yeah transmission fluid and filter i've just changed

any check engine lights?

no chek engine ligths I´m desperate :frown:

I think a trip to a tranny shop is in order for some diagnostics.

Hi thank you for your help, now i have the faulty codes:shakehead . these are p0753, p0785, p1864, p1886 i think that is weird that all these codes have trouble.
Please give me some advise.

Those codes would appear to indicate a loss of power to the transmission. The first thing to check would be the fuses. If they're all good, inspect the wiring and connections going to the tranny. If you have a remote starter check all the connections on that as well. I don't have a wiring diagram for a 95, maybe someone here can tell us which fuse goes to the tranny so that you can make sure that it has power on it while the truck is running. The problem could possibly be the ignition switch, but it's not very common for the earlier version like you have to go bad.


*Edit* If I read your reply right, this all started after you changed the fluid and filter, is there a chance that you knocked the harness loose?

*Edit* If I read your reply right, this all started after you changed the fluid and filter, is there a chance that you knocked the harness loose?

Exactly what I was thinking, and you could have knocked loose/ or damaged it when you were doing the oil/fitler change. Are you sure you didn't damage the solonoids inside the tranny when you were pulling the pan down and out, they can be damaged very easily.

What about a bad VSS?

ok i checked the trans fuse and is good then i checked the wiring harness and it looks good it is connected to the tranny. i don´t know if there is a ground wire that i should check:crying:

what is the vss? how can i check it

hicle speed sensor.

On a 4x4 I think it is on the transfer case and on a 2x4 it is on the tail shaft of the tranny.

If the computer is not getting the proper signal from it, it will mess things up completely.

hi everybody finally today i have time to remove de oil pan and check the solenoids what i found was that the 3-2 downshift solenoid was disconected now my quiestion is do you thing all these codes P0753, P0758, P1864 AND P1886 ARE FAILING BECAUSE THE 3-2 DOWNSHIFT SOLENOID WAS DISCONECTED
THANKS AGAIN FOR ALL YOUR HELP AND PLEASE GIVE ME SOME ADVISE:rolleyes:

hi everybody finally today i have time to remove de oil pan and check the solenoids what i found was that the 3-2 downshift solenoid was disconected now my quiestion is do you thing all these codes P0753, P0758, P1864 AND P1886 ARE FAILING BECAUSE THE 3-2 DOWNSHIFT SOLENOID WAS DISCONECTED
THANKS AGAIN FOR ALL YOUR HELP AND PLEASE GIVE ME SOME ADVISE:rolleyes:

Kinda hard to say but that is a good start.
Hook them all back up and clear codes and drive it and see whatit does.
Let us know how it goes.
MT

Hi again, I just plug in the solenoid that was unpluged replace the filter and tranny fluid and the truck works great, smooth shifting and everything works excellent. I really I appreciate your help and it was really helpfull i learn a lot from you. This is my first experience in the forum and I´m happy with the results thank you one more time i was sad and I was thinking in selling my blazer but now i'm very happy with my truck:) THANK YOU EVERYBODY.

Hi again, I just plug in the solenoid that was unpluged replace the filter and tranny fluid and the truck works great, smooth shifting and everything works excellent. I really I appreciate your help and it was really helpfull i learn a lot from you. This is my first experience in the forum and I´m happy with the results thank you one more time i was sad and I was thinking in selling my blazer but now i'm very happy with my truck:) THANK YOU EVERYBODY.

Thanks for letting us all know how it went.
Glad all is well.
MT

Great work!