HO2S heater resistance inspection

WARNING: This page is about a different car, the 2005 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

Disconnect the HO2S connector.
Measure the HO2S resistance between terminals C and D.
- If not within the specification, replace the HO2S.

HO2S heater resistance

HO2S (RF, LF) heater: 2-20 ohms

HO2S (RR, LR) heater: 2-50 ohms

Fig 1: Identifying Connector

Courtesy of MAZDA MOTORS CORP.