Toyota 4afe Ecu Pinout [new] May 2026

A very specific and technical topic!

Type 2: The 3-Plug “Square Plug” ECU (1992–1995)

E1:

Engine Ground (usually connected to the intake manifold). toyota 4afe ecu pinout

• TE1 (B20): Jumper to E1 (ground) to enable diagnostic mode. The check engine light will flash codes.
• TE2 (B21): Used for “test mode” on some OBD-I Toyota systems.
• VF1 (B22): Analog output for air-fuel ratio (0V = lean, 5V = rich). Used with a voltmeter for tuning without a scan tool.

The ECU uses these signals to calculate engine load and conditions: A very specific and technical topic

Type 1: The 22-Pin + 16-Pin ECU (1988–1991)

To make the 4AFE run standalone, you need to connect: TE1 (B20): Jumper to E1 (ground) to enable diagnostic mode