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· Registered
23 Posts
Discussion Starter · #1 ·
I've been trying to find an answer to the following question, but coming up with not much.
Thought I'd ask here since who knows RAV 4's better than you all!

ECU's..... Just what do they control BESIDES the transmission?

Long story short. Funky shifting, sent ecu out for repairs, now other weird stuff is happening.

As some might know, I've had troubles with my ecu.
I asked a question in a previous thread that didn't get answered, but begs to be asked again.

When I took out my ecu, all of a sudden my door clasp wouldn't work.
Now, after noticing my gas gauge was on empty (rather quickly), I went to put some gas in the tank. I put in only $10 bucks worth, and the gas gauge now shows my tank as 1/2 full!!!!

These 2 things (gas gauge + door clasp) have to be related to a faulty ecu, right? It's just too coincidental.

Anyone know for sure what else an ecu would control besides just the tanny?

· Registered
23 Posts
Discussion Starter · #3 ·
Was the ECU repaired or replaced? I would not trust a repair: the unit is just too complex. What else does it do? More than you can imagine, including door locks. Besides the ECU there are what I call compositors, or hard-wire logic junctions outside the ECU, but related.
Yes Pico! I was just reading about how they control more than we think they do. And yes, I also read about how they control the actuators around the car. So yes, it is very possible all the little problems I am having is because of the ecu.
Ok, so I bought a 2003 just about 9 months ago. Ran fine for months, then all at once, the tranny AND brakes started to act funny. Hard shift and brakes said need replacing. Sent my ecu out to circuit board medics. They have a +++A bbb rating, so I thought great. I do not know exactly what they did. I assumed they would solder the resistors and the ground points. The "repair" came with a 1 year warranty. I talked with them yesterday after experiencing new problems + the same old ones, and they said to send it back in and they will run tests to simulate the problems.
Now, besides the original reason why I sent the ecu in to be repaired (tranny shift & brakes) the car now also has problems with 1 of the doors staying closed shut and the gas gauge is not right. The repair place told me they think it's the tranny, but I am suspicious because of all these other things happening. I JUST found out the ecu also controls all the actuators around the car and many other things. When I got the ECU back from repairs, my car ran like new for a few days, then problems again, and with additional new problems. This screams ecu problems to me.

So now, this is what I am thinking.....
Buy a NEW ecu, or buy a Remanufactured one.... not a refurbished one (2 different things).
Take my car to MY mechanic. I trust him with my life, he is a great, honest guy. Ask him to see if the tranny itself is the problem. I hope there is a sure fire way to tell if it's the tranny without tearing it apart?

I have also been thinking of:
a. scrapping the whole car. Because I'm just sick of this whole thing.
b. parting it out.
c. Buying a NEW ecu and or tranny and fixing it.

I really love this car and I paid $6,200.00 for it not even a year ago.
My thoughts are.... if I have to spend 4 thousand to fix it, it's just about the same amount of money as having to go out and buy another 1/2 way decent car... and the new car might poop out and need repairs also, lol.
At least my rav looks brand new. no paint chips, scratches, dents, and the interior looks brand new to.
It just bugs me to think about putting around 11, 000 thousand into this car though. I could have bought a new dang car for that price.
Coulda, woulda, shoulda.... uggg.

Oh, here is another thing I noticed yesterday.
While driving slowly, it shifts ok into all gears. It's only when I step on it, and going through the gears fast, does the hard shifting problems happen.
Weird right?

I just want to say sorry to everyone for posting so much about these problems with my car. I just wanted to find out if they were related (and yes they are) At this point I am not going to rip off my door panel and replace the actuator, because I believe it's really the ECU causing the problems. That's why I was asking so many questions about that subject.

Now I only have 1 more question :D
If I buy a NEW ECU and install it, and find out it is the tranny causing all the problems...... will the tranny problems screw up the new ecu? And if not, and after getting a new tranny, will I have to flash the ecu, or what will have to be done to the ecu (if anything) to make it realize the tranny has been replaced?

I've also been looking here: Toyota Rav4 4WD Certified Reman Transmissions
These are remanufactured transmissions.
What do you all think of these tranny's?

I know this post is long, sorry. Just trying to figure all this stuff out.
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