Hi,

I got a reconditioned gearbox for my 04 TL Magna about 3 months ago, and ever since have had problems with rough gear changes (particularly 2nd to 3rd).

The gearbox came with a warranty and it's been back to the shop a couple of times already, but they're suggesting it could be a problem with the TCU.

I've tried the reset/training process around six times over the last couple of months, and find the gear changes improve (they're still not perfect but almost) for a day or two before becoming rough again. I commute about 80km a day with a mix of highway/city driving. I'm guessing the TCU is learning all the time, but once the gear changes are rough, they never get smooth again until another reset.

I'd be interested to know if it's common to need any work done on the TCU after replacing a gearbox, and, if so, if anyone has any recommendations for people in the Melbourne area. Otherwise, should I just keep taking it back to the same mechanic, or would it be worthwhile spending some money and taking it to a Mitsubishi dealer for a second opinion?

Thanks

Tcu is part of the ecu, generally if it does not work properly will be in limp mode. I would say issue is with trans. I have a few ecu here and is not hard to programme to work in your car but is an expensive experiment

this might not be relevant but my TE magna used to change sometimes really rough in to 2ed to 3rd, I always asumed it was a transmission issue and had it checked by mitusbishi there respons was,

this transmissions in the TE seem change rough in to 3rd due to the transmission were setup for the 4cylinder and in the v6's they strugle sometimes due to the torque difference. :nuts:

could it be a transmission from the TE?:eek2: I wouldn't know if they fit but might be worth looking in to:beer:

Michael

Do you know if the workshop that replaced your gearbox did a full flush with genuine mitsu gearbox fluid? Its very important for these gearboxes that genuine fluid is used otherwise they tend to have problems. Id also consider fitting up a transmission cooler as well. Generally speaking those magnas with genuine oil and transmission coolers fair better than those that don't.

Anyway id really push for the workshop to rectify this issue before the 3 months is up otherwise it could be costly. As mal said the tcu is in apart of the ecu so ifuou don't have a limp mode or you don't get any errors, and you've completed the relearning procedure then uouve more likely got a problem with the box itself. This can get hard to diagnose though and even harder to make the workshop comply and replce the box. It might be worth getting some proof of somesort from a mitsu dealership that the ecu is fine and not causing any problems.

Hi,

Thanks for the replies. The ECU/TCU seemed like a long shot to me as well, as I've only had problems since getting the reconditioned gearbox.

I'll take it back this week to get him to take another look. I'm actually not too far from Bayswater North, either, so will keep Mits-Fix in mind for any future work as well.

Cheers