Before checking sensors, ensure the ECU is receiving clean voltage and has a solid chassis reference.
The legendary MR2 Turbo ECU 89661-17320 (SW20 chassis) is a common platform for enthusiasts. Here is a simplified but direct pinout listing for the 3S-GTE ECU. toyota 89661 ecu pinout
| Generation | Years | Connectors | Typical Pin Count | Example Part Number | | :--- | :--- | :--- | :--- | :--- | | 4th Gen | 1996-2001 | 3 (B, C, D) | 26 + 24 + 22 | 89661-33260 (3.4L 5VZ) | | 5th Gen | 2002-2009 | 3 or 4 | 32 + 28 + 24 | 89661-06B40 (1.8L 1ZZ) | | 6th Gen | 2010-2016 | 4 (A, B, C, D) | 44 + 44 + 26 + 26 | 89661-0D150 (2.5L 2AR) | Before checking sensors, ensure the ECU is receiving
Constant 12V power from the EFI main relay when the ignition is turned on. | Generation | Years | Connectors | Typical
Verify that the crank sensor ( NE+ and NE- ) wires are shielded. Interference on these lines prevents the ECU from synchronizing engine timing.