Toyota uses a standardized 10-digit numbering system for its ECUs. Decoding this number ensures you are looking at the correct wiring diagram.
Switched +12V power supply originating from the EFI Main Relay.
: Use a compatible diagnostic tool to program a new key (requires PIN code), use immo-off tuning or immo emulator as a last resort (bypasses security), or bench program a used ECU to match your keys (requires specialized tools).
A pinout for a 89661-0D150 (2012 Camry 2.5L) is completely different from a 89661-33260 (2001 Tacoma 3.4L). You must match the full 10-digit part number .
Manifold Absolute Pressure (MAP) sensor or Mass Air Flow (MAF) sensor input. toyota 89661 ecu pinout
Ignition Switch signal. Tells the ECU that the key has been turned to the "ON" position.
What is the listed on the sticker?
: Camshaft position sensor signals (cylinder identification). VTA : Throttle Position Sensor (TPS) signal.
Common setups include 34-22-16-28 pin combinations. Toyota uses a standardized 10-digit numbering system for
On older ECUs (pre-2003), connectors are labeled E5 , E6 , E7 . On newer ones, they are A , B , C , D .
Often uses a three-plug configuration with 26-pin, 16-pin, and 22-pin connectors. Late 1990s (e.g., 1UZ-FE UCF20): Features 34-pin, 22-pin, 16-pin, and 28-pin connectors. Modern Models (2015+):
These ECUs typically feature 26-pin, 16-pin, and 22-pin yellow or grey connectors. The pin layout is usually embossed directly onto the internal green circuit board. If you open the metal casing, you will often find the acronyms (like +B , E1 , #10 ) printed right next to the solder joints of the header pins.
This specifies the exact vehicle model, engine variant, transmission type (manual vs. automatic), market destination (JDM, USDM, Euro), and production year. : Use a compatible diagnostic tool to program
Despite differences, most 89661 ECUs share a logical pin grouping. Below is a typical arrangement for a 4-connector 89661 ECU (Connectors A, B, C, D).
: For older Toyota models (late 90s to mid-2000s), pinouts are highly sought after for troubleshooting "No Start" conditions. Users report that having the correct diagram is the difference between a 10-minute fix and hours of blind testing.
Identifies the component as a Toyota/Lexus Engine Control Unit.