1st gear only is slipping/not engaging - 1999 Automatic VR4

[Davezj]

Is the auto box number the one you have in the car at the moment or is that the original one that is no longer fitted.

AutoBox: W5A513E6A is a Pre facelift box so you will need a pre facelift ECU.

but i don't know how the Facelift engine ECU will like the pre facelift box and ect for the auto.

i know the other way round is what did and it worked perfectly. i have a late PFL 1998 and it the W5A513E6B box so when i fitted the W5A513E6A box i fitted the older ECU.

so it would be worth a try i will get back to you tomorrow.

[Davezj]

ASA says your car was fitted with a W5A513E6B
so your current A/T ECU should be MR470718

My original config was:-
Box W5A513E6B
ECU MR367177 which different from yours.


How ever for a W5A513E6A box
you will need a MD761988


but i don't know if this will work on the facelift, due to the deletion of ASC and TCL on the Facelift cars.
If you can get hold of an MD761988 ecu to test if it will work, this would be you best bet.
by the way the ECU's are behind the passenger footwell ceter consol panel the engine ECU is on top and the A/T ecu is on the bottom.

the word doc below show all the A/T ECU's and Autobox for both EC5W and EC5A you just need to match up thre dates to see what ecu is matched to which auto box. But that does not mean a matched pair will work on both pre faclift model and facelift model.

Auto Box and ECU usage.doc

[Davezj]

by the way when i had the auto box ecu mismatch after changing my gear box i used my car for about 3 months i think before i worked realised it was an ecu auto box mismatch.
i just drove it in Tiptronic all the time, gear box worked perfectly, if i wanted to put it in D then i just ensured whenever i stopped, i poped it in to tiptronic changed to 2nd and slot it back into D.
you get used to doing it very quickly.

[elnevio]

by the way when i had the auto box ecu mismatch after changing my gear box i used my car for about 3 months i think before i worked realised it was an ecu auto box mismatch.
i just drove it in Tiptronic all the time, gear box worked perfectly, if i wanted to put it in D then i just ensured whenever i stopped, i poped it in to tiptronic changed to 2nd and slot it back into D.
you get used to doing it very quickly.

That sounds like the same symptoms, no?

It might thus be solvable with a swap to the correct auto ECU.

Check which one you have first. I think I have a spare you could borrow to see if it fixes it?

[kzv76]

Thanks guys, I will check asap what the ECU number is. I think you're right and the box was swapped out but the ecu remains the same and that's why its not working.

The ECU number is going to be the clincher!

If thats the correct ECU then a new autobox is the solution.

[kzv76]

The autobox is the one currently in the car. The A/T ecu is an MR470718. As suspected A/T ECU mismatch - Well done Dave & Nev!!

Nev, you say you have a spare MD761988 I could try?

Lets just hope it's compatible with the FL setup.

[Davezj]

That sounds like the same symptoms, no?

It might thus be solvable with a swap to the correct auto ECU.

Check which one you have first. I think I have a spare you could borrow to see if it fixes it?

Yes it is the same scenario with the swapping of the boxes for an earlier model but mine went into a pfl and his is going in fl with the ac and tcl removed.
So I am not 100% sure if it will work, but it is probable the best shot he has got of making it work in the cheapest possible way.

Unless the at ecu can be reflashed with the other rom image, but I have not delved into that, I know @foxdie jason has looked at a/t ecu flashing. But I don't if it is possible to do.

[elnevio]

I think the spare ECU is still in the glovebox. I'll find out about 6pm tonight when Mrs B returns with the VR-4!

[kzv76]

Thanks Nev, just let me know

[elnevio]

Thanks Nev, just let me know

Yes, I have the spare auto ECU, and it's the MD761988 one. PM me your address and I'll send it across to you to try.

[kzv76]

Thanks Nev, I really appreciate it.

Plus we can all find out if its possible to swap out a PFL Autobox into a FL and see if the old matching ECU is compatible - will post results!

[Davezj]

definitely keep us posted, it will be interesing.

it should work, i think ( i always ooozz comitment and positivity)

[kzv76]

Well..........

Success!!!!

Matching the Autobox with the correct ECU solved all the problems I had with it. It now shifts perfectly just as it was designed.

I wonder why the box was swapped out in the first place?

But anyway, we now know you can fit a PFL autobox ECU into a FL.

All you need is a matching autobox and ECU and it looks like they will work in either PFL or FL VR4's.

You guys are legends thanks so much for your help.

[elnevio]

I'm guessing the original suffered a failure! The ATF can degrade quite quickly if worked. Mitsubishi SP-III will go this way, often before the 45,000 mile service interval , Amsoil Universal ATF is by far and away the best and thrashes everything else, including SP-III. A few years ago, it wasn't uncommon for Dexron-III ATF to be used in these boxes (usually non-Mitsi garages, etc.) and problems would usually follow not too far behind.

Unfortunately, without intimate internal knowledge at Mitsubishi, or indeed the acquired knowledge here, there's not really much way of knowing what the solution is, as otherwise the boxes pretty much look the same.

I suspect the difference in your case will have come down to the fact that the facelift box will have had OWC (one-way clutch), which the PFLs did not. The oilways will flow slightly differently under different circumstances. The matching ECU means the box knows what it's doing again.


The main incompatibility problem on VR-4s appears to arise from trying to install a facelift box and ECU into a PFL, due to the mismatch regarding the AYC/ASC/TCL, which relies on an information exchange with the gearbox. Unfortunately, the change appears to require the loom and facelift AYC ECU, which is a bit of chore (minor understatement!). I don't think anyone has gone to that extreme yet?