Hi Guys

Could you help with an Auto Gearbox issue.

Our Rav4 Auto gearbox has been playing up since last week, clunking when Reverse is engaged and then jumping or having problems with 2nd gear and also loosing power.

Its 2002 petrol model – Rav4 VVTi.

I looked up and the issue seemed to be with the ECU, as a test I disconnected the negative terminal for 5 mins, the car was fine after this even the O2 sensnor light (engine light) had gone, after parking the car and driving again same problem with gearbox but engine light had come back before parking.

I took the car into an Auto specialist who diagnosed with code P0755 – shift solenoid B, see this; http://engine-codes.com/p0755.html

Since a proper reset has been done the car drives well (O2 light is back), I will test again today.

If the issue is still there I think I need to do the following; check gearbox oil level, remove and clean gearbox sump and change oil, check Solenoid !! change the dreaded ECU.

Another question ?

Will buying an OBDII reader allow me to reset the ECU at will, are they easy to use ?

If any OBDII experts out there and if you have time could you recommend an OBDII reader from ebay with the right cable, this link may help http://www.toyotaownersclub.com/foru...owtopic=130059

Ultimately I am trying to buy time with the RAV as its still a good workhorse.

Thanks again

How do you know the MIL is for the Lambda sensor and not the gearbox? Or is that a seperate light?

Most Easterly Pandas said:

How do you know the MIL is for the Lambda sensor and not the gearbox? Or is that a seperate light?

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Thanks for picking up on this...

update... Driving Rav today showed same problem in 2nd gear although reverse is much better.

I am not 100% sure if its for Lambda i am goimning by what the Indi said after the service last year.

I am very confused why the gearbox is fine after an ECU reset or when the negative terminal off for a few minutes but later the same issues arises with gearbox.

There is no binary type sequence to fault-finding this and its frustrating...

As the fault has come back should I have the transmission oil replaced in case solenoid is dirty !! if that does not work change solenoid or ECU ?

Codes attached, this may make more sense to you

all i can suggest mate is finding a pukka automotive electrical diagnostic specialist

this is outside my scope i am afraid, good luck

RobW said:

all i can suggest mate is finding a pukka automotive electrical diagnostic specialist

this is outside my scope i am afraid, good luck

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Fair comment, I will look up ECU specialists in the area.

Sadly not something i'm all that knowledgeable about arorat

It sounds like the ECU does a relearn, and then goes back to this fault, which like you say leads one to think its more an electrical issue, and possibly tolerance issue.

Just a completly random point, if it is electrical, if anything like Fiat's and Electrics, not likely to be a failing battery is it

Most Easterly Pandas said:

It sounds like the ECU does a relearn, and then goes back to this fault, which like you say leads one to think its more an electrical issue, and possibly tolerance issue.

Just a completly random point, if it is electrical, if anything like Fiat's and Electrics, not likely to be a failing battery is it

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batt is 3 yrs old and seems okay, I have also posted the topic on toyota owners club, will let you know the outcome. Will contact an ECU company tomorrow as well.

Oh bought an OBDII reader vc310 from ebay.

arorat said:

batt is 3 yrs old and seems okay, I have also posted the topic on toyota owners club, will let you know the outcome. Will contact an ECU company tomorrow as well.

Oh bought an OBDII reader vc310 from ebay.

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OTC - a great forum, but allow at least 48 hours for replies from experience

Most Easterly Pandas said:

OTC - a great forum, but allow at least 48 hours for replies from experience

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Had a reply yesterday and found http://www.ecutesting.com/ £195 for ECU test and rebuild, not bad at all.

I will remove the ecu monday and speak/send to ecutest.

I booked the ECU with www.ecutesting.com who were nice to deal with. Taking the ECU out wasn't easy due to the brackets, prob was finding a star screwdriver with a dimple, anyway a local garage obliged. Whilst wasting couple of days on sorting this out a friend who worked near BBA Reman in Rochester said he could take the ECU into them. Checking their website I noted their part no was same as mine and they offered a lifetime warranty whilst I had the car. ECU testing showed a diff part no but said they could fix it.

The ECU has been fixed or rather the TCM module on the ECU has been fixed, which I think was the problem.

After installing the ECU the auto box was hesitating a bit in 2nd to 3rd (revs would go up slightly and then change gear) but a lot better than before and after 30 miles driving all is well.

Cost £246 inc vat with BBA. ECUTESTING were charging £195 less 10% plus vat, so £210 in total. Either would have been fine but I get the lifetime warranty with BBA.