2003 corolla auto p0770 fault

[corradovr6]

Hi all,

 

i'm mainly on the yaris forum so not many posts here!

My wife has a 1.6 2003 auto Corolla.  Recently had the check engine light come on and a scan reveals the code p0770 solenoid E.  

I changed the fluid about 2 years back, although just drained it as opposed to pumping it out of the torque converter.  You can hear that it is not able to lock into direct drive on a run although the revs still appear normal and the mpg hasn't been affected.  Just looked at the fluid and it looks slightly brown, but i assume that this is because its mixed with some of the old fluid that i could get out last time.

Any pointers or suggestions to resolve?  If the solenoid is indeed at fault, it this simple to diagnose and rectify?  I've never really gone into an auto box much other than fluid change (and filters on older cars)

Many thanks

Hasan

[corradovr6]

changed the transmission fluid and filter today.  Cleaned the sump and magnet - nothing really there thankfully! Used Chempioil 3309 ATF and Blue Spot filter.  The original looked like it clicked into place, the replacement didn't but still sat flush. 3 litres added in total, this brought the level to the cold mark on the dipstick.  Warmed the car and it came to just under the warm mark.  Gear shifting seems very smooth now with almost no drag.  Cleared the fault code and took it for a short drive.  So far so good, no faults and no leaks. Will update accordingly.

[corradovr6]

Well this fault has reappeared again so i guess it must be a fault with the shift solenoid.  Is there any diagram showing the location of the solenoid, plus any things to watch out for?

Many thanks

[Parker24]

Hey there. 

Looking for some advice. I recently had the same experience. However, mine's slightly different. I have a 2002 Corolla 1.6 VVTI Auto hatchback. The car threw a check engine light after a long hot day drive. I got the code diagnosed as a single P0770 error however there was no impact to driving at all. It changed gears smoothly and there was no power reduction etc - Annoyingly my brother cleared the code and it hasn't reoccurred despite a few hours of additional driving. I suppose my question is this, I assume I'll need to wait for the car to manifest the error again before I can get this diagnosed and corrected properly and is it safe to drive in the meantime? 

Thanks in advance. 

[corradovr6]

did it change up to the overdrive smoothly?  If so, i suspect that there may have been a one-time error with the solenoid.  

What's the mileage and has the fluid ever been changed?  If not, it might just be worth doing a fluid swop plus replacing the solenoid.  Or perhaps just cleaning out the solenoid, testing and refitting. Certainly with fresh fluid you'll notice a definite improvement in gearchange.

 

if its changing ok, i dont see any issue in driving it as is, tbh, but i'm sure someone more knowledgeable can chime in.  Incidentally, the solenoid is one of the green relays (cant remember which one!)