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Discussion Starter · #1 ·
Hi, does the main ECU located in the engine compartment by the battery control both the engine and transmission for a 2011 Toyota Rav4 V6? I'm having an issue with the transmission shifting long in 2nd and hard into 3rd. First time around no light lit up but pulled a P0776. Disconnected reconnected battery after 2 hours and vehicle ran well for many miles. Problem just started again but check engine light lit up with codes P2714 and P0776. Disconnect and reconnect battery after 2 hours and everything is working perfectly again...


Is this the symptoms of a bad ECU? If something was wrong with the solenoids it would be an ongoing issue with no chance of getting many miles symptom free...


If so, what is the warranty on the ECU? Are they treated like emission control equipment with 8+ years warranty?
 

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I don't know alot about your year but i own a 2002 and the ECM is located under the glove box in the interior cabin and controls the trans & engine.
Mine was bad as were many if not all from 2001 to 2003. I believe the standard warranty applies to the ECM. Mine had a long shift from 2nd to 3rd with a double shift, also slips when down shifting from 3rd to 2nd.
I would not drive it until you remedy it or you could trash the trans (happened to alot of 2001 to 2003 rav owners). I pulled the ECM and sent it to Circuit Board Medics for repair for $210.00 and they did an excellent job.
Hope this helps a little, do more research on the web about the problem your having.
 

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Engine control module or computers are typicaly located in the cab of vehicles. Some newer vehicles have a module for transmissions also along
with one for the engine. They can also be called ECU, PCU, PCM but they are all computers with software.
Usually it is the board that fails or parts contained on the board that fails and not the software. He should find out what his codes mean and go frome there, sometimes one code will effect another area and set off another compleyely diff. code. In my case there was no check engine light hence no codes just bad shifting.
 

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Discussion Starter · #5 ·
Engine control module or computers are typicaly located in the cab of vehicles. Some newer vehicles have a module for transmissions also along
with one for the engine. They can also be called ECU, PCU, PCM but they are all computers with software.
Usually it is the board that fails or parts contained on the board that fails and not the software. He should find out what his codes mean and go frome there, sometimes one code will effect another area and set off another compleyely diff. code. In my case there was no check engine light hence no codes just bad shifting.


2011 rav4 v6 has its ECU located under the hood by the battery.


First time the issue occurred there was no check engine light lit and no codes found by Toyota, my obd2 unit picked up a P0776. They told me to leave and drive till the check engine light eventually lights up, even though they refuse to answer my question to if driving it in its present condition can damage the transmission. Disconnected the battery for 2 hours, reconnected and it ran perfectly for over 1000 miles.


1000 miles later the check engine light lights up and the vehicle has the same transmission symptoms as the first time around, My obd2 picks up a P2714 and the P0776. Disconnected and reconnected the battery and it has been shifting perfectly for over 500 miles.


It has to be an ECU issue as the P2714 and P0776 are pointing to faulty valve solenoids B and D being stuck off.


If the solenoids are indeed faulty there should be no way of having the vehicle's transmission shift perfectly for over 1000 miles just because I disconnected and reconnected the battery resetting the ECU....Disconnecting and reconnecting will not correct or repair the solenoids issue if this was the case. Unless its the ECU.
 

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Sure does sound like an ECU issue. But in my years here I don't recall a 4.3 ECU problem.
Maybe contact the Circuit Board Medics Ronstam mentioned and ask if they've repaired any 4.3 ECUs with your problem. This is probably them: www.circuitboardmedics.com
I used a different company but a couple of years ago I fixed an emissions and lighting issue on a Chrysler minivan with an exchanged ECM.

Another thought: I was making some battery voltage measurements on my V6 yesterday and saw the ECU next to the battery. I didn't really look close but the wires going into it looked pretty exposed so if you're contemplating removing the ECU anyway you might check for corrosion. Again, no 4.3 posts on it and no logic behind disconnecting the battery "fixing" it, but worth a check anyway.

Also, you shouldn't have to disconnect the battery for long if you leave the headlights on since they will take the latent charge to zero immediately.
 
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If you can locate the solenoids remove them and check the screens to make sure they are not plugged, you can also check them to see if they are operating properly. Seems the 2011 rav4 has a few problems but the ECM is not one of them. I had a simular problem as yours wih my 98 Civic and it was the trans fluid that i used when i changed it (dexron ll).
After changing it 3 times with Honda fluid the problem disapeared. Just some more ideas to think about before you rebuild the ECM.
Hope this helps
 

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I agree with Dr Dyno. Go to circuit board medics website to email them, or give them a call. I had my ecu repaired by them (I have a 2003) and they are a super nice company with a very quick response time. Your problems sound just like mine did... a hard shift between 2nd and 3rd. You should NOT drive it any further as you will risk damage to your tranny. I got my ecu back a few days ago, and my car is running like a champ now. I have read that the ecu messes up because of loose soldering points, or the ground solder points are bad. Also something to consider if circuit board medics says to send in your ecu.... they offer a spectacular warranty(s). And if they find your ecu beyond repairable, they will replace it for free! My repair cost me 209.00 and an extra 20 to ship it to them. And to think, the tranny place I took my car to told me my tranny was shot... pfffft.. Something you can check on yourself here.... If your tranny is shot, usually there will be a mixing of fluids going on (not always though). Check your radiator fluid. If you are finding tranny fluid in your radiator water, this will indicate a bigger problem. The tranny place told me that my tranny was mixing fluids because the seal was going out. I knew right away they were lying to get me to spend 4 thousand bucks. I hate it when places like that treat us as like we are stupid! :mad: Sorry you are having problems! Hopefully it will be as easy as an ecu fix. Good luck!
 

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If you can locate the solenoids remove them and check the screens to make sure they are not plugged, you can also check them to see if they are operating properly. Seems the 2011 rav4 has a few problems but the ECM is not one of them. I had a simular problem as yours wih my 98 Civic and it was the trans fluid that i used when i changed it (dexron ll).
After changing it 3 times with Honda fluid the problem disapeared. Just some more ideas to think about before you rebuild the ECM.
Hope this helps
I was going to recommend he do a drain-and-refill or two and see what happens.
 

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If you can locate the solenoids remove them and check the screens to make sure they are not plugged, you can also check them to see if they are operating properly. Seems the 2011 rav4 has a few problems but the ECM is not one of them. I had a simular problem as yours wih my 98 Civic and it was the trans fluid that i used when i changed it (dexron ll).
After changing it 3 times with Honda fluid the problem disapeared. Just some more ideas to think about before you rebuild the ECM.
Hope this helps
Very interesting Ronstam. Yes, you are right. Rav4's and Toyotas in general are very sensitive to what fluids you put in! It is best to use approved fluids. Not a plug, but if one needs help with that sort of thing, O'Reilly's has excellent service like that. They make sure you have the right stuff.... at least my O'Reilly's does. Thanks for reminding us that the proper fluids are important!!
 

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Discussion Starter · #13 ·
P2714 and P0776, they do pop up on my 2011 Toyota Rav4 V6 service manual, work shop cd, same work shop info as the dealer. Solenoid D and B.
I drained and refilled twice with Toyota WS transmission oil.
First time issues happened a few thousand miles after the first drain and fill. Disconnected, reconnect battery and drained/filled second time to see if the first time symptoms go away, it did. Another 1000 miles or so went by and the check engine light came on with P2714 and P0776. Disconnect/ reconnect battery and been problem free for about 650 miles now.
 

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Interesting, You have a one of a kind, did it also say to reset the ecm and clear the codes to disconnect the battery? There are other ways to reset.
Use your OB2 and do a reset or remove fuses and reinstall.
 

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Discussion Starter · #15 ·
So check engine, 4wd and traction light came on again yesterday with the P2714 p0776 and p0793. Took it to have the transmission oil flushed this time (Not drained and filled). All codes disappeared within 2 days of driving. P0793 is due to a rat eating through the sensors wiring a few years back in which the connector presently came loose.


Do not drain and fill the transmission fluid, have it flushed with the machine. Draining and filling will make the present debris float around and clogging the valves. Flushing removes the debris.
 

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So check engine, 4wd and traction light came on again yesterday with the P2714 p0776 and p0793. Took it to have the transmission oil flushed this time (Not drained and filled). All codes disappeared within 2 days of driving. P0793 is due to a rat eating through the sensors wiring a few years back in which the connector presently came loose.


Do not drain and fill the transmission fluid, have it flushed with the machine. Draining and filling will make the present debris float around and clogging the valves. Flushing removes the debris.
Respectfully disagree Jeff. While anything can happen anytime, my experience has been the opposite of yours. I believe regular fluid drain-and-refills is the way to go for most people. YMMV.
 

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Discussion Starter · #17 ·
My recommendation of flushing instead of drain and fill is for the V6 engines that have the U151F transmission with 4wd. The drain and fill on these transmissions will cause the solenoids to remain stuck or off.
 

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So check engine, 4wd and traction light came on again yesterday with the P2714 p0776 and p0793. Took it to have the transmission oil flushed this time (Not drained and filled). All codes disappeared within 2 days of driving. P0793 is due to a rat eating through the sensors wiring a few years back in which the connector presently came loose.


Do not drain and fill the transmission fluid, have it flushed with the machine. Draining and filling will make the present debris float around and clogging the valves. Flushing removes the debris.

There's a magnetic baffles in the oil pan that suppose to trap all the debris.
 

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Discussion Starter · #19 ·
There's a magnetic baffles in the oil pan that suppose to trap all the debris.
It won't trap the non magnetic particles from the clutch packs as they naturally wear down.
I had nothing but grief with the drain and fill, Flushing corrected all the issues.
 
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