Relay Box (Fail-Safe Relay Harness Test)

1. Turn ignition switch to OFF position. Disconnect ABS control unit 18-pin connector. Turn ignition switch to ON position. Connect terminal 2J (Black/Blue wire) of ABS control unit 18-pin connector to ground. See Fig 1 .
2. If fail-safe relay in relay box does not click or ABS warning light illuminates when terminal 2J is grounded, check fail-safe relay. See RELAY BOX (FAIL-SAFE RELAY RESISTANCE TEST). If fail-safe relay is okay, check wiring harness between fail-safe relay and ABS control unit. If wiring harness is okay, go to next step.
3. With terminal 2J grounded, check for 12 volts at ABS control unit 18-pin connector terminal 1D (Brown wire). If terminal 1D does not indicate 12 volts, check fail-safe relay and wiring harness between fail-safe relay and hydraulic unit.

Fig 1: Testing Specifications Table For ABS Control Unit Harness 18-Pin Connector

Courtesy of MAZDA MOTORS CORP.