Circuit Open/Short Inspection

Disconnect the PCM connector. (See PCM REMOVAL/INSTALLATION ).
Inspect the following wiring harnesses for open or short circuit (continuity check).

Fig 1: Identifying EGR Wiring Harness Side Connector
Courtesy of MAZDA MOTORS CORP.

Fig 2: Identifying Fuse Box (Main Relay)
Courtesy of MAZDA MOTORS CORP.

Fig 3: Identifying PCM Wiring Harness Side Connector
Courtesy of MAZDA MOTORS CORP.

Open circuit
- If there is no continuity, there is an open circuit. Repair or replace the wiring harness.
  - EGR valve terminal A and PCM terminal 2AM
  - EGR valve terminal B and PCM terminal 2AR
  - EGR valve terminal C or D and main relay terminal E
  - EGR valve terminal E and PCM terminal 2AQ
  - EGR valve terminal F and PCM terminal 2AN
Short circuit
- If there is continuity, there is a short circuit. Repair or replace the wiring harness.
  - EGR valve terminal A and power supply
  - EGR valve terminal A and body ground
  - EGR valve terminal B and power supply
  - EGR valve terminal B and body ground
  - EGR valve terminal C or D and body ground
  - EGR valve terminal E and power supply
  - EGR valve terminal E and body ground
  - EGR valve terminal F and power supply
  - EGR valve terminal F and body ground
Remove the EGR valve, and inspect for any damage or clogging.
- If there is no damage or clogging, replace the EGR valve. (See EGR VALVE REMOVAL/INSTALLATION )