Resistance Inspection (A/F Sensor Heater)

WARNING:

A hot engine and exhaust system can cause severe burns. Turn off the engine and wait until they are cool before removing the exhaust system.

CAUTION:

Do not allow flammable objects such as the taping for bundling the wiring harness to come into contact with the exhaust system such as the exhaust manifold and silencer which reach high temperatures. Otherwise, it could cause fire damage.

Disconnect the negative battery terminal. (Refer to NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION .)
Set the PCM component aside. (Refer to AIR FUEL RATIO (A/F) SENSOR REMOVAL/INSTALLATION .)
Disconnect the A/F sensor connector.
Measure the resistance between A/F sensor terminals A and E.

Fig 1: Identifying A/F Sensor Connector Terminals
Courtesy of MAZDA MOTORS CORP.
- If not as specified, replace the A/F sensor. (Refer to AIR FUEL RATIO (A/F) SENSOR REMOVAL/INSTALLATION .)
  A/F sensor heater resistance
- 1-10 ohms