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
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
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