[mangofever]

Well in case you didn't see my little post in that 20 page thread, I have a video posted which describes how to fix your rav4 ecu yourself. It takes about fifteen minutes and all you need to do is re-solder some resistors. I have verified that this is the problem, and that this is the proper fix to it. In the video description there are links to two still pics which highlight the resistors that need soldering.

Please leave comments about your successful repair so that others will know that the fix is genuine. Thanks-Jake

 

[JuneBug]

Thank you, Jake, this is very helpful. I went ahead and added your pictures to the posts.

 

[zilog357]

Thank you for such valuable info. I found the video and I was following it. I am an electronics tech but had to have my ecm repaired as I couldn't find the problem. My cousin have the same car with the same problem (only that hers is 2003) and seeing the video, I tried it without success.

I guess that it is not the same in all cases, as it improved a little, but the problem is still there and the tranny was replaced already a month ago. Anyway, I opened up my repaired ecm to confirm and those resistors did not look like it was resoldered.

I will still try it in another ecm of one of my friends. He bought his car at the same time I bought mine, but his is showing the problem now. I will post any follow up.

regards

 

[howardc64]

Just bought 2001 RAV4 135k miles for father in law. On the original un-updated ECM but no problems with transmission. The car will be out of state from me and away from my close watch. So I thought I do all preventive work on it including this ECM.

Had Toyota update the software per 60I campaign. Now having an electronic tech at work to touch up these solder joints. He provided some interesting info I thougth I share

1. When I told him about the resistor solder joints. He immediately concluded the bigger resistor's higher inertia in a car that is bouncing around might be the cause.

2. He said these circuit boards use lead free solder which becomes brittle. He used leaded solder for touch up. He said leaded solder responds much better to shaking. Using his words "it behaves like its melting"

 

[cutthroat22]

Just bought 2001 RAV4 135k miles for father in law. On the original un-updated ECM but no problems with transmission. The car will be out of state from me and away from my close watch. So I thought I do all preventive work on it including this ECM.

Had Toyota update the software per 60I campaign. Now having an electronic tech at work to touch up these solder joints. He provided some interesting info I thougth I share

1. When I told him about the resistor solder joints. He immediately concluded the bigger resistor's higher inertia in a car that is bouncing around might be the cause.

2. He said these circuit boards use lead free solder which becomes brittle. He used leaded solder for touch up. He said leaded solder responds much better to shaking. Using his words "it behaves like its melting"

That's interesting. The day mine failed I was coming back after a lot of driving on crummy forest roads and doing a lot of bouncing and shaking.

 

[MNRAV4]

1. When I told him about the resistor solder joints. He immediately concluded the bigger resistor's higher inertia in a car that is bouncing around might be the cause.

wrong conclusion IMO

SMD solder joints often fail if there is a CTE (coefficient of thermal expasion) mismatch between the part (resistor) and the bare pcb

the problem is more likely to also occur on a physically large resistor, the problem is well known with large ceramic smd resistors because of the CTE mismatch to the epoxy glass based pcb

but those do not look like ceramic resistors, which are more square shaped and thinner, nether-the-less it does appear that it may be a solder joint problem, the years in question were the early years of lead free solder and that could very well be the problem.

Mine is a 2003, but as I am in the if it ain't broke, don't fix it school, I won't be touching mine until it needs it

 

[Thunder-Bolt]

Mine is a 2003, but as I am in the if it ain't broke, don't fix it school, I won't be touching mine until it needs it

I don't know what to do.

My car drives beautifully but it does jerk some when changing gears while not moving. Like if I go in reverse or back into drive. Not bad , but
it's a jerk for sure.

I feel like I should get it done but hate the idea of messing with something if it's running great.

Then I think it might be too late if I keep driving the Rav causing more damage and then I might need things replaced and that costs money.

Plus these services for the rav on ebay and the guy here in NYC just trade your ECM out and they put in their repaired ECM. I don't like that idea. I rather have my original ECM in my car.

Oh what to do !

PS: Plus the Toyota website says my car is one of them and that I should bring it in to get serviced. Doesn't say if it's free of cost being I missed the 10 year mark and not sure if I still can do it free of cost being I'm under the 150,000 mark.

 

[howardc64]

I don't know what to do.

My car drives beautifully but it does jerk some when changing gears while not moving. Like if I go in reverse or back into drive. Not bad , but
it's a jerk for sure.

I feel like I should get it done but hate the idea of messing with something if it's running great.

Then I think it might be too late if I keep driving the Rav causing more damage and then I might need things replaced and that costs money.

Plus these services for the rav on ebay and the guy here in NYC just trade your ECM out and they put in their repaired ECM. I don't like that idea. I rather have my original ECM in my car.

Oh what to do !

PS: Plus the Toyota website says my car is one of them and that I should bring it in to get serviced. Doesn't say if it's free of cost being I missed the 10 year mark and not sure if I still can do it free of cost being I'm under the 150,000 mark.

Soldering repair on this thing is pretty trivial, experienced ebay service vendors is not going to mess up the old ECM. ECM removal is also pretty easy. I did it just as a preventive measure since not my car.

Get yours done for $100 or so and see if the problem is still there. Seem like good preventive medicine against the cost of a transmission replacement.

 

[Thunder-Bolt]

Soldering repair on this thing is pretty trivial, experienced ebay service vendors is not going to mess up the old ECM. ECM removal is also pretty easy. I did it just as a preventive measure since not my car.

Get yours done for $100 or so and see if the problem is still there. Seem like good preventive medicine against the cost of a transmission replacement.

Ebay service vendors state..you pay..they send you a repaired ecm (not yours) ..then you have to send your old one back to them. If you don't send back the old one they will charge you for not sending it back. So you don't get the credit back/returned.


Think I'll make some calls ..I rather they fix my ECM then use another one that has been fixed.

PLus some say it's a re-programmed ECM and no mention of any soldering.

Very confusing.

 

[howardc64]

Ebay service vendors state..you pay..they send you a repaired ecm (not yours) ..then you have to send your old one back to them. If you don't send back the old one they will charge you for not sending it back. So you don't get the credit back/returned.


Think I'll make some calls ..I rather they fix my ECM then use another one that has been fixed.

PLus some say it's a re-programmed ECM and no mention of any soldering.

Very confusing.

google "rav4 ECM repair"

A bunch of links that will service your ECM rather than swap modules.

 

[Keninblaine]

I had my ECU repaired by chkengine in Brooklyn in Oct 2012 and the car has run perfectly ever since. But the other day it wouldn't engage Reverse (Drive was fine). I left it and came back in 2 hours to try again, but this time the car wouldn't start (lights etc all worked, but nothing from the starter). I checked that there was battery voltage at the starter and that the ignition lead at starter showed voltage when turned to start position, and determined it had to be the starter. I replaced the starter, but on initial re-start attempt it didn't work. But on second attempt it did start AND engaged Reverse successfully. But then an hour later, it wouldn't start again (the starter doesn't operate when the key is turned). Everything checks out at the starter terminals. So I'm suspicious of my ECU.

Does anyone know if a faulty ECU could affect the starter function?

 

[eric42]

Thank You!

Thank you Jake! After parking our 2001 RAV4 for about 6 months, I was experiencing very erratic shifting. I had no issue before parking. I thought it was the transmission. I don't have money to get that repaired and was stressing a bit. Then I found your video which showed me a quick, easy, free fix.


All I had to do was reheat the existing solder on those 6 transistors which fixed the issue.

May God bless you!

 

[Mach III]

Got trouble with the ecu on my 2003 model, and found the solution to the problem in the youtube video and this thread. Took a closer look at the ristors under a microscope before I resoldered them, and you can see the small crack on the photo attached her. Shifting is now ok again, even though there still is some juddering under heavy load, will replace the atf fluid now and hope for the best that not discs in the atf allready is damaged. Thank you very much for this easy solution!:smile

 

[Mach III]

Got trouble with the ecu on my 2003 model, and found the solution to the problem in the youtube video and this thread. Took a closer look at the ristors under a microscope before I resoldered them, and you can see the small crack on the photo attached her. Shifting is now ok again, even though there still is some juddering under heavy load, will replace the atf fluid now and hope for the best that not discs in the atf allready is damaged. Thank you very much for this easy solution!:smile

View attachment 35418

Hmm, still problems between 2-3 gear, + engaging reverse which has a lag of about 2 seconds. Maybe I should have measured the resistance of the resistors, and not just resoldered them?

 

[ponsai03]

ECM/Transmission problem for 2001-2003 RAV4

Hi: This video on how to repair your ECU is very helpful and definetely a $$$$ saver. My 02 Rav4 began having this issue with erratic shifting at about 120,000 on the odometer. It feels like it wanted to take off from second gear and also when engaging into reverse it makes a very noticeable sound and vibration. After searching the web, answers began to appear right away pointing to the same symptoms my truck had.
I ran the vehicle with this condition for about 200 miles. Found this guy in ebay that makes the repair for the ecu for $150. For this price and with so many postings indicating the same diagnostic I proceed to send my ecu. Three days later, received the unit, install it and problem solved!!!!!! So far my 02 has 173,000 and still runs like if it was new.
Bottom line, if you are having this issue, I will recommend fixing your own ecu if you feel you can do it or go for the alternative I did. Just avoid dealers which will charge you ridiculous amount of money.

 

[Ramsey24]

hi ponsai03
I have same problem with my rav4 2003 , can you please send me that link in ebay for repair ecu ? thanks
email : [email protected]




regards

 

[blu_bil]

Same here

Hmm, still problems between 2-3 gear, + engaging reverse which has a lag of about 2 seconds. Maybe I should have measured the resistance of the resistors, and not just resoldered them?

Just re-soldered identified resistors and took it for a drive. Majority of problems; sporadic shifting, hard clunking shifts, have disappeared. However now there is a consistent problem between 2nd and 3rd. The transmission hesitates, either revving up to 4k rpm during high acceleration, or sort of faltering with moderate acceleration.

Thought maybe I should try retouching my solders, but interesting you had the same result Mach III. What did you end up doing?

I think I may have to give in and send it off. Does anybody know a shop north of the border (Canada)

 

[Mach III]

Just re-soldered identified resistors and took it for a drive. Majority of problems; sporadic shifting, hard clunking shifts, have disappeared. However now there is a consistent problem between 2nd and 3rd. The transmission hesitates, either revving up to 4k rpm during high acceleration, or sort of faltering with moderate acceleration.

Thought maybe I should try retouching my solders, but interesting you had the same result Mach III. What did you end up doing?

I think I may have to give in and send it off. Does anybody know a shop north of the border (Canada)

I ended up sending the ecu to a shop in Bulgaria (I live in Norway myself). I think the only thing they did was reprogramming the ecu again, I could not see that they had done anything physical inside the unit. So it seems that even if the resistors gets resoldered/replaced, the ecu have to be reprogrammed again. My car have driven just fine after I got the ecu back from Bulgaria, for abouth 3 months/5000 kilometres now. :smile

 

[bachphi]

I MENTIONED THIS SOMETIME AGO AND NOBODY PAID ATTENTION TO IT.

besides 6 resistors were re-soldered, there is a transistor. (B906) right next to the 820 resistors also re-soldered.

Matter of fact, since the ECM was soldered using non-lead, and the bigger the transistors/resistors may not get good connection, why not resolder them all. Flip the board over and resolder the big ones too.

 

[Rav4Repair]

What makes you all so sure that the solder used in those ECMs is lead free? Because it is not. It looks like that because of the process used to assemble the unit. The resistors is just part of the problem, not the problem itself. Those are current sensing resistors, used to record the current amount passing to the solenoids and then populate the transmission adaptation table memory with proper codes for a better shifting. Resistance value is low (0.33 ohms) as to not significantly lower the current going to the solenoids, while sensing the voltage drop across the resistors to calculate the current draw at different times.

I see that there are still many "shops" on trial and error (playing) with these units. That is why we receive so many units poorly worked out and needing extra repair, specially coming from eBay.

Please guys, be careful who you buy a service from on eBay. Some units that many of those "shops" tried to repair are then sent to us by those customers in a second attempt to repair their ECMs.

Some units are left unrepairable as there are some of those "shops" that after doing their non-working job, they cover the circuit with some epoxy, leaving the unit impossible to be reworked without damaging the circuit board. I have seen others putting underrated parts, like a 25v capacitor, where the original is 50v. They must be saying, "well, it is a 12volt system, so a 25v capacitor will work". They do not even take in account the internal switching power supply of the ECM, that generates voltages higher than 25v. Some other put a lot of solder in the grounds, taking as true, the myth of the poor ground problem in the screws area. Summarizing, they are just playing to make an easy buck and won't refund a cent when it fails, giving the excuse that it must be the transmission. In some case, it is the transmission, but in the majority of the cases, it is only the ECM.