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Repair ECU Manual For Toyota RAV4 Automatic Transmission Control Units

overview the problem and causes

many American RAV4, produced in 2001-2004, suffer from typical malfunctions of the engine control unit and automatic transmission .The problem is the transmission does not change or other problems like this.

It is rare for errors to occur in the mechanical part of the transmission The automatic machine itself is quite reliable

but because the control unit is located near the heater motor. It is fixed very rigidly, which leads to microcracks on the massive elements of the board ECU .

List of ECUs (incomplete) that can managed to repair

This listing is for the ECU that could be experiencing the same problem, You can make it as a reference to see if your ECU is in this list :

  • Serial number in ECU 89661-42820
  • Serial number in ECU 89661-42661
  • Serial number in ECU 89661-42681
  • Serial number in ECU 89661-42680
  • Serial number in ECU 89661-42890
  • Serial number in ECU 89661-42760
  • Serial number in ECU 89661-42761
  • Serial number in ECU 89661-42662
  • Serial number in ECU 89661-42810
  • Serial number in ECU 89661-42821
  • Serial number in ECU 89661-42651
  • Serial number in ECU 89661-42660
  • Serial number in ECU 89661-42682
  • Serial number in ECU 89661-42683
  • Serial number in ECU 89661-42652
  • Serial number in ECU 89661-42653
  • Serial number in ECU 89661- 42720
  • Serial number in ECU 89661-42821
  • Serial number in ECU 89661-42A50

Typical DTCs:

  • Fault code stored Shift Solenoid "A" (SL1) Malfunction or Shift Solenoid A/B Malfunction (malfunction of solenoid A)
  • Fault code stored Shift Solenoid "A" (SL1) Electrical Malfunction (electrical malfunction of solenoid A)
  • Fault code stored Shift Solenoid "B" " (SL2) Malfunction or During Normal Driving
  • Fault code stored Shift Solenoid "B" (SL2) Electrical Malfunction
  • Fault code stored  Linear Solenoid for Line Pressure Control Circuit Malfunction or Shift Solenoid Valve SLT Fault or Linear Solenoid for Lock-Up Control Circuit Malfunction (SLT solenoid malfunction).

Now step by step to repair the ecu

ECU Toyota RAV4
The first interface
ECU Toyota RAV4
Second interface

Thoroughly solder the component of ECU with rosin or good flux (not acid or soldering grease) 6 microcircuits circled in yellow.

Also carefully solder 8 resistors on the top side of the board and 7 resistors on the bottom side of the board, circled in red.

Unsolder the 25080 chip circled in purple, read it from the programmer and save the dump! This point is extremely important, because in the key chip, in case of problems, the car will not start!

In the pictures below there are two dumps. Original and corrected. The blue highlighted area should be filled with zeros. Addresses: 100-1FF

ecu rav4
original dump

eeprom rav4
dump modified

After correction, write a new dump back onto the microcircuit EEPROM , solder it back. The block is ready.

The first few kilometers will be spent adapting the gearbox, possibly lowering the idle. It will pass soon.

We put the ECU in place. We start the engine and let the throttle valve warm up and adapt. A lot has been written about adaptation too.

overview The immobilizer in this ECU

the immobilizer is built into the engine control unit it exist in EEPROM 25080 , the keys have Texas 4C transponders with a fixed code, and a reading device is connected to the engine control unit - which reads the code from the key transponder and compares it with what is stored in a non-volatile EEPROM with an SPI interface - 25080. In addition keys, it stores the adapters of the box part, and resetting the settings for a test (training - after repairing the unit on the box or repairing the box itself)

The same types of engines for the North American market came without an immobilizer, with a regular iron key - and this can be used to disable the immobilizer


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