Ecu Pinout: 2uzfe

| Pin | Wire Color | Function | Signal Type | | :--- | :--- | :--- | :--- | | E5-1 | Black/White | ECU Main Relay (B+) | 12V Battery | | E5-2 | Black/Orange | Backup Power (Memory) | 12V Constant | | E5-10 | White/Red | Injector #1 | Switched Ground | | E5-20 | Brown | EGR Vacuum Switching Valve | Switched Ground | | E5-25 | White/Black | Power Ground | Chassis Ground | | E5-26 | Brown | Power Ground | Chassis Ground |

Pro Tip: Pins E5-25 and E5-26 must have a clean ground. If these are loose, the ECU will reboot randomly while driving.

Before diving into pins, understand that the 2UZ-FE uses a Toyota EFI system (TCCS – Toyota Computer Control System). The ECU (Engine Control Unit) controls not only fuel and spark but also electronic throttle control (on later models), knock control, VVT-i (Variable Valve Timing with intelligence), and automatic transmission logic (when paired with the A750F or A343F). 2uzfe ecu pinout

There are two distinct generations of 2UZ-FE ECUs:

Crucial Warning: The pinouts between these generations are not interchangeable. Using a 2002 ECU wiring diagram on a 2006 engine will result in immediate electrical conflict. | Pin | Wire Color | Function |

Before looking at pins, you must identify your engine harness/ECU year. The 2UZ-FE went through three main phases:

Note: The diagrams below primarily apply to the 2000–2004 Non-Drive-by-Wire (Cable Throttle) ECUs, typically found in Tundras/Sequoias (Engine Code 89661-0D...). Crucial Warning: The pinouts between these generations are

The most critical for a successful start.

If you have an engine from a 2005-2007 Tundra or 2006-2011 Land Cruiser, stop using the chart above. You need the "Electronic Throttle Control System" pinout.

Key Differences: