Insulation resistance of Case

WARNING: This page is about a different car, the 2004 Mazda 3. However, it is still accessible from the selected car via links, so may be relevant.

Disconnect the ignition coil connector.
Measure the insulation resistance from terminal A to ignition coil case using an ohmmeter.
- If not as specified, replace the ignition coil.
1. Resistance (Reference) Above 10 megohms [25 °C {77 °F}]
  
  Fig 1: Measuring Insulation Resistance Between Terminal A & Ignition Coil Case
  Courtesy of MAZDA MOTORS CORP.