Short Circuit

No.1 cylinder fuel injector connector terminal B and PCM connector terminal 2A to GND.
No.2 cylinder fuel injector connector terminal B and PCM connector terminal 2D to GND.
No.3 cylinder fuel injector connector terminal B and PCM connector terminal 2G to GND.
No.4 cylinder fuel injector connector terminal B and PCM connector terminal 2J to GND.

Fig 1: Identifying Harness Side Connector Terminals Of Mail Relay
Courtesy of MAZDA MOTORS CORP.