It looks like i have fried my auto trans cpu, has anybody changed one and can tell me where it is. all i have been told is its behind the dash somewhere in a ridiculasly hard spot to get at. it looks like my alternator fried it. Already took it to an auto trans guy and thats what he said it was and quoted $500 to supply and fit. Any help would be great as i currently have a huge paperweight blocking my driveway.

Well, I'm certainly no expert and hopefully somebody who knows better will chime in. But, I think you should be right to switch TCU's as long as its from the same model vehicle. as in I dont think the TCU is coded to the ECU or BEM.

Wreckers may have what you're after. Just don't mention "$500" until after they've sold it to you for $50.

And as for getting to it... I've never done one. The workshop manual indicates that its up under the dash, toward the center console maybe.

It looks like i have fried my auto trans cpu, has anybody changed one and can tell me where it is. all i have been told is its behind the dash somewhere in a ridiculasly hard spot to get at. it looks like my alternator fried it. Already took it to an auto trans guy and thats what he said it was and quoted $500 to supply and fit. Any help would be great as i currently have a huge paperweight blocking my driveway.

This is a V6 TE? In the V6 TE, TF and TH autos the TCU function is built into the same circuit board as the ECU, but is run by a separate microcontroller chip from the ECU. So replacing the TCU involves replacing the whole ECU assembly, which will involve sorting the immobiliser.

The 2.4 TE/TF autos appear to have had a separate TCU.

The ECU is located at the forward end of the centre console at or slightly above pedal level. Removing the driver's footrest will get you access to that side, and removing the passenger side centre console panel gets access on that side (though apparently if you know what you're doing this isn't really required).

thanks guys it kinda helps, i just don't no exactly what it looks like so i might find it and not realise. the model is 2001 verada 3.5 v6. apparently it is a seperate unit and the only other advice i got was " did ya try near the gear box" LOL im not a mechanic but im not a complete idiot either. at least now i have a bit more direction

You will need to replace the ECU (ECU+TCU are combined), and since this for a KJ you will need to also make sure it is 4sp tippy, and flash it with your immob code, or turn the immob off.

Turn the immobiliser off? You can do that?

thanks guys it kinda helps, i just don't no exactly what it looks like so i might find it and not realise. the model is 2001 verada 3.5 v6. apparently it is a seperate unit and the only other advice i got was " did ya try near the gear box" LOL im not a mechanic but im not a complete idiot either. at least now i have a bit more direction

Hmmm... a KJ - this is definitely the one microcontroller doing both engine and transmission. If you still have normal engine operation, the ECU itself is operating normally. If there is connection problem, the good news is that the immobiliser issue is easy to deal with if you can find someone to reflash a replacement (even a Mitsubishi dealership). If the engine won't start then the ECU probably is dead.

The ECU itself is in a black plastic casing about 18*16*3cm with 4 connectors facing (as mounted in the car) to the rear of the car.

Assuming you have a running engine, I would however start by downloading the workshop manual (searching the forums should turn up the link) or buying a 3rd party workshop manual. There is a procedure which can be used to check any ECU diagnostic codes via blinking the dash lights. This might help identify the problem.

The next step is to check the ECU connectors, making sure they're all firmly plugged in and that there are no loose wires, and then check the continuity of each wire between the ECU and the transmission.

there is no problems with the ecu side of things, the car starts no worries idles fine and the rest, its just that i had trouble with it going in to gear and jumping out again at low speed. then the next day was fine, then dramas again for a while then fine again. then it dropped into limp mode but is now out of limp mode and wont go into any gear.

the AT guy looked at it and said it was definately electrical and quoted to put a new module in but said i could do it myself (which considering it stuck in the driveway i have no choice) but no-one has said anything about the imobilizer, i thought it was a seperate unit altogether. does it interface with the ecu and recognise a different unit has been installed?

I know this sounds simplistic, but try resetting the ECU by disconnecting the battery for 30 seconds or so. You may be surprised.

the AT guy looked at it and said it was definately electrical and quoted to put a new module in but said i could do it myself (which considering it stuck in the driveway i have no choice) but no-one has said anything about the imobilizer, i thought it was a seperate unit altogether. does it interface with the ecu and recognise a different unit has been installed?

The immoboliser will only be an issue if you change the ECU (the ECU and the immobiliser interface with each other and have to be programmed with mutually known codes for the car to start).

As Hako posted, start with an ECU reset. If that doesn't change the behaviour...

It is possible that one of the ECU output circuits that drive the transmission was damaged by the alternator without affecting the rest of the ECU, but as this is relatively unlikely I'd check all the wiring before fronting up for a replacement ECU. While locating the ECU for testing, be sure to note the part number and other markings on the sticker on the casing - knowing this will make it a lot easier to find a replacement from wreckers.

Also if you can find someone else to look at it, a second opinion might be worthwhile.

thanks guys for the advice, I replaced the alternator so had it disconnected for longer than 30 sec, ( anybody that has done one knows how long that is) still no go, apparently they are in one unit but they are a package deal with the bem and keys. In other words to replace the ecu without flashing you have to replace the BEM and the ring around the barrel and the keys.

I don't know how to flash with just the security codes without changing the factory parremeters for the running of the car and the nearest dealer is about 50k away and they want it on site to reflash a new ECU so it all came out and is sent of to be reco and i hope its worth it.

thanks for all the help tho

pocko where are you located? I have an openport 1.3u and can flash the ECU with a new security code for you. Will be back in Sydney tomorrow morning.

Life, I am located near newcastle, but i sent the ecu and bem of to be reconditioned, and i just got them back with no fault found. Plugged it in and guess what??? still not going into gear. if anyone has had same issues and had it resloved some help would be great. But for now i have a 1.4 ton paperweight blocking my driveway.

Life, I am located near newcastle, but i sent the ecu and bem of to be reconditioned, and i just got them back with no fault found. Plugged it in and guess what??? still not going into gear. if anyone has had same issues and had it resloved some help would be great. But for now i have a 1.4 ton paperweight blocking my driveway.

Find another auto trans specialist to look at it - it could well be a gearbox problem if the ECU checked out okay.