: Intake manifold pressure (MAP) or Mass Air Flow (MAF) sensor signal. THW : Engine Coolant Temperature (ECT) sensor. THA : Intake Air Temperature (IAT) sensor.
Searching for the engine code (e.g., "1ZZ-FE pinout") alongside the 89661 number often yields better results than the part number alone. Could you provide the full 10-digit part number engine and year of your Toyota so I can find the exact wiring diagram?
Ignition Trigger signals sent from the ECU to the igniter/coils to spark. toyota 89661 ecu pinout
Misinterpreting the view perspective will mirror your wiring layout, causing catastrophic damage to the ECU upon power-up. 5. Safe ECU Wiring and Bench Testing Best Practices
| 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) | : Intake manifold pressure (MAP) or Mass Air
Permanent +12V constant battery power (used to keep ECU memory/trims alive).
Crankshaft position sensor signals used for engine speed (RPM). Searching for the engine code (e
Almost all 89661 ECUs from the late 1990s to the 2010s use three or four large rectangular connectors. On the ECU case, these are typically labeled:
| | Pin # | Name / Label | Function | | :--- | :--- | :--- | :--- | | A | A20 | IGT – TACH + | Ignition Control Module (IGT) / Tachometer Signal | | A | A15 | G1 | Power Ground (for ECU's internal high-current drivers) | | B | B6 | OX | Oxygen Sensor (Primary O2 sensor signal) | | B | B4 | KNK | Knock Sensor (Signal used to detect engine knocking) | | B | B12 | IDL | Idle Switch (Part of TPS, signals closed throttle) | | B | B9 | E2 | Engine Sensor Ground (Ground reference for sensors) | | B | B11 | VTA | Throttle Position Sensor (TPS) Signal | | C | C2 | VS | Throttle Switch (Another TPS signal for load detection) | | C | C1 | VC | +5 Volt Sensor Power Supply (Vcc to TPS, MAP sensors) | | D | D4 | BRS | Brake Switch (Signal for ECU to know brake is applied) | | D | D9 | VSS | Vehicle Speed Sensor (Speed signal to ECU for idle, etc.) |
use large multi-row connectors. Detailed guides are often found on enthusiast sites like Lextreme .
Below are the most common pin abbreviations and terminal layouts used across the 89661 series: Common ECU Pin Abbreviations