| Pin | Function | Signal Type | Typical Color | |-----|----------|-------------|----------------| | B1 | Engine coolant temp (ECT) | 0-5V analog | Green/Yellow | | B2 | Intake air temp (IAT) | 0-5V analog | Yellow/Black | | B3 | Throttle position sensor (TPS) signal | 0-5V variable | Gray/Red | | B4 | TPS reference voltage (5V) | +5V | Light Green | | B5 | TPS ground | Sensor ground | Brown/White | | B6 | MAP/MAF signal | Frequency or 0-5V | Pink/Black | | B7 | MAP/MAF ground | Sensor ground | White/Black | | B8 | Knock sensor | AC signal | White | | B9 | Camshaft position (CMP) | Digital | Yellow/Blue | | B10 | Crankshaft position (CKP) | AC or digital | Black/White | | B11 | Sensor ground common | 0V reference | Brown | | B12 | +5V sensor supply | +5V | Light Green/Red | | B13 | Oxygen sensor front (signal) | 0-1V | White | | B14 | Oxygen sensor rear (signal) | 0-1V | White/Black | | B15 | VSS (vehicle speed) | Square wave | Violet/White | | B16 | Neutral safety switch (auto) | Ground or 12V | Blue/Yellow | | B17 | Power steering pressure switch | Ground | Red/Black | | B18 | A/C request signal | 12V | Blue/Black | | B19 | A/C amplifier feedback | 0-5V | Yellow/Green | | B20 | Electrical load signal | 12V | Red/Yellow | | B21 | Starter signal (STA) | 12V crank | Black/White | | B22 | Battery voltage sense | 12V | White/Red |
When diagnosing a 89661 ECU, follow these standard procedures:
A customer had a 2001 Toyota Tacoma that cranked but would not start. Using the 89661-33260 pinout:
Without the pinout, the mechanic would have spent 4 hours guessing. With it, the diagnosis took 15 minutes.
A full Toyota ECU part number looks like:
89661-XXXXX (e.g., 89661-06A90, 89661-33240, 89661-52N10)
⚠️ Never assume pinout from the prefix alone. Always use the full 10-digit number on the ECU label.
Look for the full 10-12 digit number on the ECU case label: toyota 89661 ecu pinout
Example: 89661-2F210 (2002 Camry 2.4L)
^^^^^^
This suffix is critical
Without the suffix, a generic pinout is impossible.
Despite the vast differences between variants, the 89661 family retains a common electrical philosophy. The following circuits are almost always found on the same relative positions or same color wires across the series.
The Toyota 89661 ECU pinout is not just a picture of a plug. It is a road map to your engine’s brain. Whether you are reviving a dead Camry, swapping a 2JZ, or building a full race car, you cannot succeed without the correct wiring diagram.
Final checklist before you splice or probe:
A wrong pinout costs you time and money. The right one makes you a wiring hero.
Do you have a specific 89661 ECU pinout question? Drop your full part number in the comments below, and we will help you locate the correct diagram. | Pin | Function | Signal Type |
Toyota 89661 is the base part number prefix for a massive range of Toyota Engine Control Units (ECUs). Because this prefix spans decades of vehicles—from 1980s Corollas to modern Land Cruisers—the specific pinout depends entirely on the five digits following the prefix (e.g., 89661-50170). Common Pinout References
While specific diagrams vary, many Toyota 89661 series ECUs share standardized pin abbreviations and basic power configurations:
BATT (#14 on some V8 models): Constant 12V power from the battery. +B / +B1 (#22, #23): Switched 12V power from the EFI relay. IGSW (#9): Ignition switch signal to wake up the ECU.
MREL (#13): Output signal to the EFI relay to provide main power.
E1 / E2 / E01: Various ground points for the chassis and sensors.
VC / VTA: Power and signal for the Throttle Position Sensor (TPS). Without the pinout, the mechanic would have spent
NE+ / NE-: Crankshaft position sensor signals used for engine speed (RPM).
THW / THA: Temperature signals for Engine Coolant and Intake Air. Pinouts for Specific Engines
If you are working on a popular swap or classic model, these are some common 89661 configurations: 1UZ-FE (Lexus/Crown V8): Models like 89661-50170 or 89661-50241
use large multi-row connectors. Detailed guides are often found on enthusiast sites like Lextreme.
1JZ-GTE / 2JZ-GTE (Supra/Soarer): These typically feature 40-pin, 80-pin, or similar high-density connectors depending on whether they are VVTi or non-VVTi. 4A-GE (MR2/Corolla): Older models like the 89661-17190 use yellow plugs with a 26/16/22-pin layout. How to Find Your Specific Diagram
Because "89661" covers so many different modules, use these steps to identify your exact wiring: Toyota 89661 ECU Pinout: Find 89661-50241 Pinouts