Rav4 Problems After Ecu

[tjlock2010]

Hi all i have had auto transmission problems on rav4 2002 clunky gears obd codes p0750 (shift solenoid a)

also over revving going in to 2nd gear intermittently.

So i had the ecu tested and fixed by ecu testing reinstalled

and all the issues have gone no clunky gears juddering or codes pinging up

but i am still left with the intermittent over rev changing to 2nd gear.

I have looked at the transmission fluid and it is a bit dirty and im not sure if its low as i seem to get inconclusive readings if i start the car leave it running for 20 mins but don,t drive it then it looks low to me but if i drive it for 20 mins and check it looks OK

which do we think i take as the correct reading as i am seeing mixed answers on the net.

so do i send ecu back to be looked at again or chase up the fluid issue?

Thanks for any help

[firemac]

Did you follow ECUt's fitting instructions to the letter? It's very important that you do to ensure that the ECU is starting again from its baseline; these things use fuzzy logic to "learn" your driving style but they will also learn unwanted parameters if drive is engaged before the engine and drivetrain have reached full operating temp before first use.

Otherwise, as ECUt provides a lifetime warranty, it might not do any harm to send it back to be re-checked just to eliminate any ECU issues before you start fiddling with the gearbox. There are conflicting opinions on whether it's a good idea to change the ATF: some say it can dislodge sediment that will then cause further problems whilst others feel that the new fluid improves the box's performance generally. Bear in mind that unless you remove the box from the car, it is impossible to drain all the ATF - the bit in the torque converter can't be drained in-situ.

If the ECU is OK then I'd guess that the re-commissioning process went wrong or the box suffered mechanical problems coincidentally with the ECU being away for re-flash.

Good luck.