In today's video I replace the Purge Valve on a Chevy Sonic 1.8. This fixed my P0443 code. NOTE that the code is not only caused by a bad purge valve.

What causes the P0443 code?
The ECM has commanded the purge control valve to open and detected either an incomplete open circuit or a short in the circuit.

The cause of code P0443 can be a purge control valve internal open circuit or the connector is corroded causing loss of contact with the valve.

The code can also be set if the wiring to the valve is damaged between the ECM and the purge valve causing an open circuit if the wire is cut or a short if the wire is shorted to ground or a power source.

What are the symptoms of the P0443 code?
The Check Engine Light will be illuminated and the code is set in ECM memory.

You may notice a slight drop in fuel mileage if the vapor system is not working.

How does a mechanic diagnose the P0443 code?
Scans codes and documents the code in the ECM, views the freeze frame data see when the fault happened

Inspects the entire vapor purge valve wiring and system to include the purge valve connector for corrosion, damaged or loose connection or wires

Checks the purge valve vent for any blockage from dirt, debris, or spider webs

Performs a smoke leakage test on the fuel vapor system to try and locate the cause of the vapor leak using the test vapor port

Checks the purge control valve for proper resistance of valve and then check operation of valve using the ECM to control the valve

Common mistakes when diagnosing the P0443 code
Not checking and assuming the purge control valve is defective without doing a thorough diagnostics of the complete system to later find the wiring is broken or cut

Not verifying the failure and replacing parts that may or may not be the problem

How serious is the P0443 code?
Code P0443 causes the check engine light to go on and this alone will cause a failed emission test.

The code means the fuel vapor system control valve is defective or the circuit to it is not making the connection to the valve so the ECM lost control to the valve.

The vapor recovery and reuse system if not working correctly can cause a loss of fuel mileage.

What repairs can fix the P0443 code?
Testing and replacing the purge control valve
Repairing the damaged wiring to the purge control valve and secure from getting damaged again
Replacing the purge vent valve

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