Circuit Open/Short Inspection

1. Disconnect the PCM connector. (See PCM REMOVAL/INSTALLATION ).
2. Inspect the following wiring harnesses for open or short circuit (continuity check).
   Fig 1: Identifying Fuel Injector Harness Connector Terminals

   Courtesy of MAZDA MOTORS CORP.
   Fig 2: Identifying Main Relay Harness Connector Terminals

   Courtesy of MAZDA MOTORS CORP.
   Fig 3: PCM Harness Connector Terminal Identification

   Courtesy of MAZDA MOTORS CORP.

Open circuit 

• If there is no continuity, there is an open circuit. Repair or replace the wiring harness.
  • Fuel injector No.1 terminal A and PCM terminal 2BB
  • Fuel injector No.2 terminal A and PCM terminal 2BC
  • Fuel injector No.3 terminal A and PCM terminal 2BD
  • Fuel injector No.4 terminal A and PCM terminal 2AZ
  • Fuel injector No.1 terminal B and main relay terminal A
  • Fuel injector No.2 terminal B and main relay terminal A
  • Fuel injector No.3 terminal B and main relay terminal A
  • Fuel injector No.4 terminal B and main relay terminal A

Short circuit 

• If there is continuity, there is a short circuit. Repair or replace the wiring harness.
  • Fuel injector No.1 terminal A and body ground
  • Fuel injector No.2 terminal A and body ground
  • Fuel injector No.3 terminal A and body ground
  • Fuel injector No.4 terminal A and body ground