Vibration Method

If a malfunction occurs or becomes worse while driving on a rough road or when the engine is vibrating, perform following the steps:
NOTE:
- There are several reasons why vehicle or engine vibration could cause an electrical malfunction. Some of the things to inspect for:
  - Connectors not fully seated.
  - Wiring harnesses not having full play.
  - Wires laying across brackets or moving parts.
  - Wires routed too close to hot parts.
- An improperly routed, improperly clamped, or loose wiring harness can cause wiring to become pinched between parts.
- The connector joints, points of vibration, and places where wiring harnesses pass through the firewall, body panels are the major areas to be inspected.
- Inspect for DTCs or malfunctions by slightly shaking wiring harnesses and connectors that are suspected of causing the malfunction.
  
  Fig 1: Shaking Wiring Harnesses And Connectors
  Courtesy of MAZDA MOTORS CORP.