Toyota 89661 Ecu: Pinout Verified

The Ultimate Guide to the Toyota 89661 ECU Pinout: Diagnostics, Swapping, and Wiring

If you are a Toyota technician, a JDM engine swapper, or a DIY mechanic chasing an electrical gremlin, you have likely stumbled upon a silver box with the number 89661 stamped on the side. The Toyota 89661 series ECU (Engine Control Unit) is one of the most common engine computers found across a vast range of Toyota vehicles, from the legendary Land Cruiser and Hilux to the Corolla, Camry, and RAV4.

Check for BATT: Do you have 12V at the ECU with the key off? If not, your ECU won't remember timing trims or fault codes. toyota 89661 ecu pinout

• Pin A1 — BATT (constant 12V)
• Pin A2 — IGN (switched 12V)
• Pin A10 — GND
• Pin A15 — VREF 5V
• Pin A20 — CKP input
• Pin A21 — CMP input
• Pin A30 — CANH
• Pin A31 — CANL

• Part number format: 89661‑XXXXX (suffix changes by model and market). Labels often include manufacturer (Denso/Hitachi).
• Common connector sizes:

  Communication: CANH (Pin 11) and CANL (Pin 19) are standard for many 2015+ models on the A38 connector. Ground (E1): Frequently located at C45-81. 3. Older Models (22RE, 1UZ-FE, 1JZ-GTE) The Ultimate Guide to the Toyota 89661 ECU