Help!

[Deanomo]

Hi All

We have Toyota Yaris 1.0L T3 MMT on a 2004 plate which we've had a few problems with as of late. A few months ago the car wasn't going into gear which would happen intermittently and always when stopped at a junction with the engine running. Now it is a bit nasty between gears in auto and revs very high before setting off. We've been into the local RRG Toyota who have told us it is the MMT ECU that needs replacing at a cost of £1300. I've seen on the forums that some companies do a refurb/repair of ECU units and so I have a couple of questions:

1. Has anyone experienced this problem before? If so is the diagnosis of the MMT ECU correct?

2. If it is the MMT ECU are there any reputable repairers that anyone can recommend?

3. Is the MMT ECU the same as the ECU: I know this is under the glove box and has part number 89661 OD180: If this isn't the right box where is the one I need and how do I remove the ECU (whether it's the one under the glove box or elsewhere).

All help is greatly appreciated.

Dean

[Cyker]

Seen quite a few Aygo MMT owners with this issue; The (kludgy) fix is apparently to get Toyota to reset the MMT ECU every time the car's serviced (I think you could do it now by disconnecting the Battery for a minute or so, but don't quote me on that!)

Replacing the ECU doesn't seem to help as the problem re-appears after a period of time. The problem seems to be in the 'learning' part of the MMT, but wiping that part with a reset every now and then seems to make it better.

It could also be the MMT clutch parts are wearing out tho', but that's also an expensive thingn to check so try the reset first!

[Deanomo]

A BIG thanks for the info. Im a total dork with cars so forgive me if I ask simplistic questions. When you say disconnect the Battery do you mean disconnect the terminals from the car Battery? RRG told us we needed the unit replacjng at a cost of 1300 quid bless em. I dont believe them.

[Cyker]

Yeah, that's the quick and dirty way of resetting the ECU AFAIK but I don't know if it'll mess anything else up. Hopefully someone here who actually knows stuff about cars can chip in

[Madasafish]

Dean

All you need to do is disconnect the earth lead on the Battery - the one with only one set of wires - usually nearest to you as you peer under the bonnet.. and leave disconnected for 30 minutes. Make sure you switch off the engine first and remove keys from switch.

Then reconnect and switch on and start up. Everything reset..

It should clear any engine code errors stored in the ECU..

It may solve your problems or not.. But.. it's free!

[Deanomo]

Cyker and Madasafish I want to say a BIG thanks to both of you. I disconnected the Battery and left it for a while and then took the car out on a test run. Everything is great with changes at 2-2.5K or 3 if it's booted. Also went on the motorway and hit the kickdown, got it to 80 and all great. I did get one stall at my first junction (ECU "learning" perhaps?) but after that it ran like a dream. Hopefully we're cured and I'm a grand plus better off.

Thanks a lot chaps!!!!!!

[Madasafish]

Dean

Glad it's fixed..

My fee is 10%.

[Cyker]

Glad we could help! :D

[Deanomo]

Sincerely guys I'm really grateful for your help. Thanks a bunch.

[sfoister]

these MMTs seem to have lots of issues... my one is slightly different to this. But heh, as you say, this is free. I'll give resetting the ecu a go... what harm can it do?