2003 Matrix- P0770 code

[panthermike]

Posted another thread here but now turned into more mechanical issue potentially: https://bobistheoilguy.com/forums/t...cm-relearn-toyota-matrix.405221/#post-7537924.

This transmission sometimes is shifting kind of firm I would say. Goes into all the gears, no hesitation, or perceived slippage. Thought it was shifting much more consistently yesterday afternoon and suddenly got this code on the way home. I have seen fixes range from dirty fluid, valve body, solenoid itself, possibly even the speed sensor. Would the intermittent firm shifts be a solenoid issue?

Little history- 12 quarts of fluid have gone through it in the last week and a half over several drain and fills. On the second one I replaced the transmission filter and added Lubegard. It's only been a couple hundred miles total since the new fluid. I have cleared the code and so far has not returned (but only driven 20 or so miles). Hoping the LG can work some magic here.

Driving this car 1,500 miles next Friday so want to be sure it's up to snuff!

 

[martinq]

It looks like this would be the A246E transmission? Do you know where to find Toyota service info / TSBs, etc?

 

[panthermike]

It looks like this would be the A246E transmission? Do you know where to find Toyota service info / TSBs, etc?

Yes sir! I heard there is a TSB for this issue but can't find it. Found one link on a Toyota forum but the link is dead now.

 

[martinq]

https://www.transmissiondigest.com/toyota-u341e-f/

This has some information for the P0770 code in a different Toyota transmission but I'm sure there's some overlap.

"Code P0770 is a mechanically generated code for the lockup solenoid, which Toyota calls the SL solenoid. The code basically represents anything that can cause the converter clutch to slip. If it were an electrical code indicating a problem with the wiring from the computer down to the solenoid, or the solenoid itself, code P0773 would be set."

 

[panthermike]

https://www.transmissiondigest.com/toyota-u341e-f/

This has some information for the P0770 code in a different Toyota transmission but I'm sure there's some overlap.

"Code P0770 is a mechanically generated code for the lockup solenoid, which Toyota calls the SL solenoid. The code basically represents anything that can cause the converter clutch to slip. If it were an electrical code indicating a problem with the wiring from the computer down to the solenoid, or the solenoid itself, code P0773 would be set."

Helpful thank you. The issue with this code is that sometimes it's not the Solenoid itself. Many have replaced it and the code returns at some point. I don't have equipment to test the solenoids, wonder if there's an easy shadetree mechanic way of testing them?

 

[dogememe]

If this is the same as the Corolla it's a pretty common issue.

 

[panthermike]

If this is the same as the Corolla it's a pretty common issue.

Yes, same transmission. If there's an easy place to start, I'm willing to dig in. But as long the car works, I may not worry about it. My FIL won't be doing a ton of driving anyways in the small Iowa town he lives in.

 

[martinq]

Another take on the P0770 code in a Toyota Transmission:

https://www.transmissiondigest.com/rav4s-transmission-dilemma-presents-challenge/

"2000 Toyota RAV4
...
The code chart for the P0770 shift-solenoid-E malfunction has a simple description of the diagnostic trouble code (DTC) checking condition: It says that the lockup does not occur during lockup range (50 mph) or lockup remains on during lockup-off range. The possible causes listed are that the shift-solenoid valve is stuck open or closed, the valve body is blocked or stuck, or the clutch is locked up.
...
The transmission shop picked up the vehicle and took it back to the shop. They decided to try one more solenoid on it before tearing it back apart. The owner of the shop called me to report that they did find that the solenoid was sticking and the new solenoid took care of the problem."

 

[martinq]

Also, remove / clean / inspect your battery connections and grounds!

https://www.transmissiondigest.com/simple-fixes-for-bad-battery-connections/

"1999 Toyota 4Runner which had the dash light on. This was our transmission that was purchased about three weeks earlier, so I scanned it and there was a P0770 code (solenoid E electrical).
...
I cleaned and reinstalled the negative cable all the way onto the battery post. I cleared the codes and delivered the vehicle back to the customer."

 

[martinq]

One more log on the fire. I'm guessing you may have already found this one:

https://www.toyotanation.com/thread...245e-shift-solenoid-e-location-p0770.1683902/

"Just a quick update for the p0770, after going back in and testing all the shift solenoids to be in spec. (11-25 ohms) I cleaned them down again. Especially because they are slightly magnetized and metal residue will appear.
...
After replacing the ~3.5 liters of ATF fluid and driving the car on a little road trip the CEL has turned off."

 

[The Critic]

https://www.transmissiondigest.com/rav4s-transmission-dilemma-presents-challenge/

Here's some background. You might want to get a $20 subscription to alldatadiy to get the official troubleshooting info and check for any applicable TSB's.

 

[panthermike]

One more log on the fire. I'm guessing you may have already found this one:

https://www.toyotanation.com/thread...245e-shift-solenoid-e-location-p0770.1683902/

"Just a quick update for the p0770, after going back in and testing all the shift solenoids to be in spec. (11-25 ohms) I cleaned them down again. Especially because they are slightly magnetized and metal residue will appear.
...
After replacing the ~3.5 liters of ATF fluid and driving the car on a little road trip the CEL has turned off."

That's a novel idea, I may try to just clean them first. I don't have a lot of time to do diagnostics on it unfortunately. As a last ditch effort if needed, I may try to get a set of solenoids from a junkyard and swap them in. These solenoids new are crazy expensive!