This bulletin applies to 2013-2019 Chevy Malibu vehicles equipped with a 2.0L engine. The MIL may be on, accompanied by DTC P0172 (fuel trim system rich) set in the ECM. The condition may be caused by driving the vehicle in short intervals, allowing excess fuel to collect in the crankcase.

Replacing fuel components such as the high pressure fuel pump or fuel injectors will not correct the setting of P0172 under short interval driving conditions unless those components can be verified as causing a fuel rich condition.

NOTE: Stable battery voltage is critical during programming. Any fluctuation, spiking, over-voltage or voltage loss will interrupt programming. Install a GM authorized programming support tool to maintain system voltage. If not available, connect a fully charged 12V jumper or booster pack disconnected from the AC voltage supply. Do not connect a battery charger.

Program the ECM to the latest software available. Remove the camshaft cover. Remove the PCV valve from the cover. Apply a light coating of oil to the revised PCV valve O-ring. Note that the PCV valve has been revised for 2016-2019 models. Only the new style PCV valve should be installed.

Using hand pressure, install the PCV valve into the cover until seated into its bore. Install the camshaft cover.

An oil and filter change is necessary to remove excess fuel from the crankcase. Clear the code and test drive the vehicle to confirm that the code does not return.

The revised PCV valve is available as P/N 55596783.

The PCV valve for 2016-2019 models has been revised. Install only the new design. The old design (A) is shown at left; the new design (B) is seen at right.

The PCV valve for 2016-2019 models has been revised. Install only the new design. The old design (A) is shown at left; the new design (B) is seen at right.

Lightly oil the new PCV valve’s O-ring and hand-install until fully seated in its bore.

Lightly oil the new PCV valve’s O-ring and hand-install until fully seated in its bore.

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