Climate Control Exhaust Gas Sensor: Service and Repair

Air Quality Sensor (G238)

• The air quality sensor is not installed in all vehicles (optional equipment at this time).

• The air quality sensor is a highly sensitive electronic component that can be damaged if it comes in direct contact with solvents, fuels or chemicals (e.g. impurities may enter through area - A -). Do not install an air quality sensor that may have been stored in a tool box.






• Do not store a removed air quality sensor in areas that are contaminated with solvents, fuels and certain other chemicals (fluids or gases).

• Air Quality Sensor (G238) is available in different housings, but functionally they are the same. Refer to Electronic Parts Catalog (ETKA).

Removing and Installing

- Lift right side of plenum chamber cover or remove plenum chamber cover.

- Disconnect connectors - A - from air quality sensor.






- Rotate air quality sensor 90° and pull air quality sensor - B - upward out of mount.

Terminal assignment in connector - A -

1 B+ (terminal 15)
2 Ground (terminal 31)
3 Signal line to the Climatronic control module (J255) (the measured value is displayed in the measured value block of the Climatronic control module using Vehicle diagnosis, testing and information system (VAS5051B) in "Guided Fault Finding" function).

• Square wave signal cannot be evaluated using workshop equipment.