A/F Sensor Heater Inspection

1. Disconnect the negative battery cable. (See BATTERY REMOVAL/INSTALLATION .)
2. Disconnect the A/F sensor connector.
3. Measure the resistance between A/F sensor terminals A and E.

• If not as specification, replace the A/F sensor. (See AIR FUEL RATIO (A/F) SENSOR REMOVAL/INSTALLATION .)

A/F sensor heater resistance 

1-10 ohms 

Fig 1: Air Fuel Ratio (A/F) Sensor Terminals

Courtesy of MAZDA MOTORS CORP.