It is possible to conduct a Toyota ECU repair without having the whole vehicle in a garage. The ECU (or electronic control unit) is a small item fitted with ports that controls the actions of the transmission. If you know how to take it out, you can send it off for diagnosis and repair in the mail, often with a 24 hour turnaround.
The ECU is located behind the glove box. To access it, first open the Toyota Rav 4 glove box. Then remove the lid of the glove box, which requires the use of a screwdriver. The open faceplate and the internal box should come out together.
Now you need to remove the side trim. The side trim is located where the external body shell sill meets the floor pan on the passenger door side. When the side trim has been removed you will see wires extending along the sill. The curved side trim panel that goes up the side of the foot well must also be taken out.
The ECU is the grey box revealed behind the glove box. To the left, a security bracket is held in place with a series of bolts. Remove the bolts and take off the bracket.
There is a lower screw on the bracket beneath the glove box, revealed by the removal of the larger piece of side trim. Take this off too. You may now remove a pair of 10mm bolts from the security bracket, and remove the ECU connectors (they look like old monitor ports for desktop computers).
The ECU and its bracket may now be slipped out by dropping the unit into the space where the side trim was, and pulling it out through the foot well.
It is possible to disabuse whether the unit needs a Toyota ECU repair by connecting it to diagnostic software. This may be done at any Toyota dealership, or any garage with the required equipment. You can even do it yourself if you have the tools. Alternatively you may send the unit for diagnosis to a by mail repair location. The mail repair partner will determine whether the ECU is the problem, or whether you may have to look at other issues.
You may, if you wish, eliminate the potential mechanical issues that could be affecting the gearbox of the Rav 4 by investigating its flywheel and the gear bolt. On 4 speed models made between 2000 and 2004, a known flywheel issue on the diesel versions can cause the mechanics of the transmission to fail. The flywheel bolts loosen their hold when these vehicles have been used to perform maximum effort work at low differential. This is a known issue but one for which the extended warranty has long run out, and may be expensive to fix.
The five speed Rav 4 for the period up to 2005 also has a known gear bolt issue – this time with the bolt loosening in fifth gear. Again, the mechanical damage done may require a significant transmission rebuild, which can be expensive.