Toyota 89661 Ecu — Pinout ^new^

Ignition feedback signal (if the ECU doesn't see this, it will cut fuel). #10, #20, #30: Injector pulse signals. Troubleshooting Tips for 89661 ECUs

) have high-density connectors requiring pinouts for CAN communication (CANH/CANL) and digital ignition signals. Standard Pin Functions toyota 89661 ecu pinout

When testing a running engine, insert your probe from the wire side of the connector to avoid stretching out the metal terminals. Ignition feedback signal (if the ECU doesn't see

| Pin | Signal | Notes | |-----|--------|-------| | A1 | +B (12V main relay out) | Powers ECU internal drivers | | A2 | +B1 | Same as +B | | A3 | MREL | Main relay control (ECU grounds to turn on relay) | | A4 | FC | Fuel pump control (circuit opening relay) | | A5 | #10 | Injector cylinder 1 | | A6 | #20 | Injector cylinder 2 | | A7 | #30 | Injector cylinder 3 | | A8 | #40 | Injector cylinder 4 | | A9 | IGT1 | Ignition trigger cylinder 1 | | A10 | IGT2 | Ignition trigger cylinder 2 | | A11 | IGT3 | Ignition trigger cylinder 3 | | A12 | IGT4 | Ignition trigger cylinder 4 | | A13 | IGF | Ignition confirmation feedback | | A14 | E01 | Power ground (injectors/coils) | | A15 | E02 | Power ground | | A16 | E03 | Power ground | Standard Pin Functions When testing a running engine,

Understanding the is critical. A single miswired sensor can cause no-start conditions, transmission shifting errors, or irreversible damage to the ECU’s driver circuits. This article provides a master-class breakdown of the 89661 ECU architecture, common pinout configurations by vehicle model, diagnostic procedures, and how to source the correct wiring diagram for your specific 5-digit suffix.

| Connector | Typical Pin Count | Common functions | |-----------|------------------|------------------| | (or E1) | 22–26 pins | Power, grounds, injectors, ignition coils, fuel pump relay, main relay | | B (or E2) | 22–26 pins | Sensors: TPS, MAP/MAF, ECT, IAT, O2 sensors (primary), VVT solenoid | | C (or E3) | 16–22 pins | CAN bus (if equipped), speed sensor, AC request, alternator L terminal, check engine light, diagnostic port (SIL, TC, TS), O2 sensor (secondary), EGR, purge VSV |