Mitsubishi auto trans/Reverse went out completely. (NOT slipping)

[mullins1971]

I have read many posts on this forum and got a lot of help on my 91 Eclipse but my work car now has a problem and I couldn't find any matching posts. I have a 1997 Galant ES (2.4L with F4A23 Transmission) Reverse went out all at once, never slipped, just acts like it is in neutral. I pulled pan and no shavings or debris were found (just normal powder on magnets) fluid dirty but not burnt smelling, dark in color but still had red cast to it. pulls good in forward gears but seems like overdrive is not engaging. Checked for codes and had P1750 (solenoid malfunction) cleared code and drove but code did not reset. I do most all of my own work but am having trouble finding good info on this. I've been told everything from o-ring to needs overhaul. I need to know if this is electrical problem or internal such as band problem. I have never seen a band go bad without slipping first. Is this band adjusted behind servo at right front of trans? Any help would be greatly appreciated

 

[Mike Croutcher]

Does the car start out in 2nd or 3rd gear, and not go into overdrive also?
If so then check the pulse generators.

If it works fine I bet it is either a bad solenoid for reverse, or a wire broke to the reverse solenoid.

Mike Croutcher (I'm back)
Diamond Star Specialties

 

[mullins1971]

Starts out in low like it should and changes 1-2 and 2-3 normally but does not go into overdrive (switch is on but acts like it is off) which solenoid in valve body controls reverse. Thanks for your help

 

[LeosTalon]

Does the car start out in 2nd or 3rd gear, and not go into overdrive also?
If so then check the pulse generators.

If it works fine I bet it is either a bad solenoid for reverse, or a wire broke to the reverse solenoid.

Mike Croutcher (I'm back)
Diamond Star Specialties

Hey I'm new to dsmtuner. With the oil pan off you should check the resistance of every solenoid (it should have a low resistance value). It could be as simple as a solenoid. If money is not an issue then overhaul it. Otherwise look for the cheapest thing, like a solenoid. Is the transmission oil level correct? I have done diagnosis, overhauls, and r&r on rear wheel drive trucks with auto trans for years but these cars are all new to me. Same concept though.
If you alredy checked for correct oil level, codes, visual inspect the trans, and debri in the oil pan and found nothing wrong then drop the trans for overhaling. Having found nothing wrong, the only choice is to bring down the trans and open it.

 

[VTEC_lol]

it doesnt sound good either way.

 

[jusroln]

I've been told that reverse cannot fail because of electrical issues. You could unplug all electrical connections to the trany and the reverse should work. You might have a plugged valve body or transmission pump. I would start by taking apart and cleaning the valve body. If that doesn't fix it, move to the pump.

 

[leathalkreation]

Same thing happened toe with my 2g but I'm on my third rebuild
. And 6 grand later I pulled codes before I pulled the tranny buy my problem was my solenoid assembly there about 225 throuh ipt transmission. My car lost reverse all together all at one with no warning then the rest of the gears went I got the P1750 code also and I tested my solenoids and thee dead no lose wires there shot. But if you change them translab shift kit is a good deal and works great even with my solenoids going bad it shifted like a beast and I didn't even have it set to the firmest setting.