IG1 Power Source Circuit

Ensure charging system is working properly. Repair as necessary. Turn ignition on. Measure voltage between ABS ECU connector terminals IG1 and GND. See ECU POWER SOURCE TERMINAL IDENTIFICATION table. Battery voltage should exist. If battery voltage does not exist, go to next step. If battery voltage exists, replace ABS ECU.
Check resistance between ABS ECU connector terminal GND and body ground. Resistance should be one ohm or less. If resistance is not as specified, repair or replace wiring harness or connector as necessary. If resistance is as specified, check ECU-IG fuse, located in fuse box.
If fuse is okay, check for open in wiring harness and connector between ABS ECU and battery. If fuse is not okay, check for short in all wiring harness components connected to ECU-IG fuse. See appropriate wiring diagram under WIRING DIAGRAMS.

ECU POWER SOURCE TERMINAL IDENTIFICATION

Application ⁽¹⁾

ECU Terminal (Wire Color)

1997 Paseo

Power

A15-5 (Black/Yellow)

Ground

A14-7 (White/Black)

1997 Tercel

Power

A12-5 (Black/Yellow)

Ground

A13-7 (White/Black)

1998 Tercel

Power

A12-9 (Black/Yellow)

Ground

A13-8, 16 (White/Black)

⁽¹⁾	See Fig 1, Fig 2 or Fig 3.

Fig 1: Identifying ABS ECU Terminals (1997 Paseo)

Fig 2: Identifying ABS ECU Terminals (1997 Tercel)

Fig 3: Identifying ABS ECU Terminals (1998 Tercel)