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OBD Codes > Mercedes-Benz > p0146

Mercedes-Benz Information

DATSC provides free error code information for Mercedes-Benz vehicles and is provided free of charge.

Mercedes-Benz is a German manufacturer of automobiles, buses, coaches, and trucks. Mercedes-Benz is a division of its parent company, Daimler AG. Mercedes-Benz traces its origins to Karl Benz's creation of the first petrol-powered car, the Benz Patent Mot

Country & Continent of Origin: Germany (Europe)

O2 Sensor Circuit No Activity Detected


Symptoms of a P0146 DTC may include: MIL (Malfunction Indicator Lamp) on May idle or drive poorly Fuel economy may decrease


Potential causes of an P0146 code include: Bad Bank 1, position 3, o2 sensor Wiring problem, melted harness, broken connectors, etc. Bad PCM


1. Start the engine and allow it to reach operating temperature. Using a scan tool, observe the Bank 1 position 3 o2 sensor. If it isn't moving between 0.1 and 0.9 volts, increase the engine RPM to a fast idle and then recheck the sensor voltage reading.


The catalytic converter is used to control emissions. The o2 sensor on Bank 1, position 3 is aft of the converter and monitors the catalyst efficiency. The PCM (Powertrain Control Module) does this by comparing the post-cat o2 sensor to the pre-cat o2 sen