My TR magna 2.6 litre auto transmission will only select 3rd gear.
Reverse and neutral function as normal, however remains in 3rd gear even if lower gear selected.
Won't downshift on acceleration either.
Will not go into overdrive.
Have tried selecting power/economy mode but this makes no difference.
Even when vehicle is stopped, still remains in 3rd and engine labours until car gets up to speed.
Thanks for your time.

disconnect the battery terminals for a minuite to reset the computers
reconnect battery terminals

if the auto keeps playing up then you may need a computer unit controller

DIY

you need to by a second hand Transmission controller from the wrecker
to suit your car they often give trouble

location ask at the wrecker

unplug the wiring plugs and reconnect

the mechanical side of the box should be ok if your oil is red and not burnt
and you have forward and reverse gears


link http://www.mitsubishiclubaustralia.com/for...topic.php?t=824]

Thanks for that info and the quick response, Chain Rattle
I had in mind that it might be the electronics. I have recently had problems with my voltage regulator and the alternator output has been running higher than normal, which has probably put some stress on the controller. That's fixed now.

I've taken out the glove box and passenger kick panel and can only find the ECU there. I've asked 3 wreckers for a price and to advise where to find the TCU ???, all of whom have quoted exactly $275 and have said something like "behind the console somewhere". Quite a coincidence about the price. I might draw some conclusions about this!

If you or anyone else can be more specific about how to get at the TCU, it would save me pulling apart more than I need to.
Another request...can anyone point me to some info on how to perform electrical tests on transmission and/or TCU, which might require only a multimeter and basic tools.
Any advice on how to confirm what the problem is would give me more confidence that I am not wasting my $275.
I've seen mention in other forums of resistance checks and continuity checks.
Thanks again.

posts in link should help


http://www.mitsubishiclubaustralia.com/for...opic.php?t=3284]

the tcu diagnostic plug is near the fuse box on the drivers side

Thanks, found it. Tested the TCU and found faulty (no signal on diagnostic pin). Got a new one from eBay. Total damage $65. Plugged it in and transmission is working normally.
I'm totally wrapped. A great forum. Thanks for your help.

good to get feedback when these forums help owners

I have 92 Magna and I just had the gearbox computer go and it did the same thing.That means that your gearbox computer is had it.I found you dont have to follow the same numbers like everyone tells me so.Just get any one out off the same model or near yours.

Hi Ppl...okay i hav a 94 magna v6 and it just happened the other day where as i get up to speed it wont change into 4th...ive listened and its changing all the way up to about 60km...but then it just keeps reving but wont change.
Its hitting 3000revs at 80kms...thats not right is it??

I have no idea what to do..ive read this forum & il take the info to my dad to help but honestly i hav no clue & dont wanna get ripped off cos im a chick who knows nothing...which has happened before...so if anyone can HELP ME! id really appriciate it...

and member laymans terms please haha

SO yur saying its shifting 1-2 , 2-3 and then nothing after that? Are just reving when it goes to change to 4th gear? . or its starting off in 3rd gear when in Drive and staying in third?

its goin from 1 -2, 2-3 then nothing...it wil just contine to rev...so when i get to 80kms its at 3000revs and it doesnt sound pretty so ive been driving slower...but its just whack!

So i wanna know what the options are to fix it, if you know any :)

If i am understanding correctly , when it is supposed to go frum 3-4 it acts like its in neutral?

Its common on older KM (F4A22 , F4A23 , F4A33 transmissions) if it seems that when sposed to go into 4th it does notthing , just rev. The friction clutches for the 4th gear are overly worn. And the transmission would need to be rebuilt.

nah its not goin in neutral, the car is stil driveable, its stil accelerating its just not changin up the gears into 4th...so the revs just keep climbing instead of changing into 4th & the revs go down abit so the car isnt driving so hard.

I think Kates automatic V6 has
worn end clutch/overdrive friction and drive disks
a quick fix

Thanks guys i really appriciate your help :blush-anim-cl: