Error P0443 – how to fix it?

P0443 code definition

Fuel vapor emission control system purge control valve circuit failure

What does the P0443 code mean?

P0443 is a generic OBD-II code that indicates that the engine control module (ECM) has detected a fault in the purge control valve or its control circuit. This may indicate a break or short in the valve or circuit.

What causes the P0443 code to occur?

• The ECM has ordered the purge control valve to open and has detected an open circuit or incomplete short circuit.
• The cause of code P0443 may be an open circuit within the purge control valve or a corroded connector causing loss of contact with the valve.
• The code can also be set if the valve wiring 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 to a power source.

What are the symptoms of the P0443 code?

• The Check Engine light will come on, and the code will be stored in the ECM memory.
• If the vapor system is not operating, you may notice a slight decrease in fuel mileage.

How can a mechanic diagnose the P0443 code?

• Scan the codes and document the code in the ECM, review the freeze frame data to see when the fault occurred.
• Check all wiring and the steam purge valve system, including the purge valve connector, for corrosion, connections, damaged or loose wires.
• Check that the purge valve opening is not clogged with dirt, debris, or cobwebs.
• Performs a smoke leak test on the fuel vapor system to try to locate the cause of the vapor leak using the test vapor port
• Tests the resistance of the purge control valve, and then checks the valve operation using the ECM to control the valve.

Most common errors when diagnosing P0443 code

• Not checking and assuming that the purge control valve is defective without performing a complete diagnosis of the entire system and then determining that the wiring is damaged or cut
• Not checking for the fault and replacing parts that may or may not be causing the problem.

How serious is the P0443 code?

• The P0443 code causes the check engine light to come on and this fact alone results in a failed emissions test.
• This code means that the fuel vapor control valve is defective or the circuit does not connect to the valve, causing the ECM to lose control of the valve.
• The vapor recovery and reuse system, if not functioning properly, can cause a loss of fuel mileage.

What fixes can clear the P0443 code?

1. Check and replace the purge control valve.
2. Repair damaged wiring to the purge control valve and protect it from being damaged again.
3. Replace bleed valve

Additional notes on code P0443

The P0443 code is a fairly common code that vehicles arrive at today and causes the check engine light to come on. The most common cause is accidentally lowering the fuel cap or not tightening it enough after refueling. With this code, the most common fault is that the vent control valve has an internal open circuit or the vent valve does not stop steam.