Toyota 89661 Ecu Pinout Better Jun 2026

The pinout configuration changes drastically based on the engine series and connector style. Common "89661" series include: 1UZ-FE (Lexus/Celsior V8): Often found in part numbers like 89661-50241 (1994–1997) or 89661-50102

Note: Pin A1 must have constant 12V even with engine off. Loss of this pin erases adaptive fuel trims and causes rough idle. toyota 89661 ecu pinout

Never probe or depin an ECU with the battery connected. The pinout configuration changes drastically based on the

Look at the label on the ECU. Example: 89661-60A70 (2006 RAV4). If the label is gone, check the original vehicle’s VIN sticker under the hood or door jamb. Never probe or depin an ECU with the battery connected

| Pin | Signal | |-----|--------| | B1 | VTA (TPS signal) | | B2 | VC (TPS 5V reference) | | B3 | E2 (TPS ground) | | B4 | THW (Engine coolant temp) | | B5 | THA (Intake air temp) | | B6 | VG (MAF signal) | | B7 | EVG (MAF ground) | | B8 | OX1 (Front O2 sensor signal) | | B9 | KNK (Knock sensor) | | B10 | VVT+ (not used on this non-VVTi) |

💡 Always measure voltage at the ECU pins while the engine is cranking. A pinout might show 12V at +B , but if that drops below 9V during cranking, the ECU may reboot or fail to fire the injectors.