P0443 Evap Purge Solenoid Circuit

When monitored code P0443 - with the ignition on or engine running, battery voltage greater than 10.4 volts, evap purge solenoid control active above 20% duty cycle. Set condition, the PCM compares the circuit feedback to a calibrated closed rannge when the circuit is de-energized or to a calibrated open range when the circuit is energized. A fault is determined if the value is out of the calibrated range in either the de-energized or energized state for more than a calibrated amount of time. Default actions, the MIL light will illuminate.

Possible causes:

• Evap purge control circuit shorted to voltage.
• Evap purge control circuit shorted to ground.
• Evap purge control circuit open/high resistance.
• Evap purge solenoid.
• Powertrain Control Module (PCM).

Diagnose code P0443 Evap Purge Solenoid Circuit

Step 1. Vehicle history and service bulletin investigation

Turn the ignition on, with the scan tool, record the related freeze frame data. Check the following items which may assist in repairing the customers complaint succesfully.

• Check the vehicle repair history. If the vehicle has a repair history that pertains to the customers current complaint, review the repair.
• Inspect the vehicle for any aftermarket accessories that may have been installed incorrectly.
• Check for any service bulletins related to customers complains or DTC. If a service bulletin applies, follow the instructions per the service bulletin.

Chose the following scenario that best applies.

The service bulletin repaired the customers complaint, testing complete.

A DTC is present, the vehicle inspection revaled no concerns, no service bulletins apply, or the service bulletin did not repair the customers complaint, go to step 2.

Step 2. Check for an active DTC

Start the engine and allow it to idle long enough for the evap purge solenoid to become active. With the scan tool, read DTC and record the repair order.

Is the DTC active or pending?

YES, go to step 3.

NO, perform the PCM intermittent Condition.

Step 3. Check the evap purge control circuit for a short to voltage

Turn the ignition off, disconnect the evap purge solenoid harness connector. Disconnect the PCM harness connector. Check for continuity between the evap purge control circuit and all other at the PCM harness connector.

Is there continuity between the evap purge control circuit and any other circuit?

YES, repair the evap purge control circuit for a short to another circuit.

NO, go to step 4.

Step 4. Check the evap purge control circuit for a short to ground

Check for continuity between ground and the evap purge control circuit at the evap purge solenoid harness connector.

Is there continuity between ground and the evap purge control circuit?

YES, repair the evap purge control circuit for a short to ground.

NO, go to step 5.

Step 5. Check the evap purge control circuit for an open/high resistance

Measure the resistance of the evap purge control circuit from the evap purge solenoid harness connector to the PCM harness connector.

Is the resistance below 3.0 Ohms?

YES, go to step 6.

NO, repair the evap purge control circuit for an open or high resistance.

Step 6. Check the evap purge solenoid return circuit for an open/high resistance

Measure the resistance of the evap purge solenoid return circuit from the evap purge solenoid harness connector to the PCM harness connector.

Is the resistance below 3.0 Ohms?

YES, go to step 7.

NO, repair the evap purge solenoid return circuit for an open or high resistance.

Step 7. Check the evap purge solenoid

Reconnect the PCM harness connector, start the engine. With the scan tool, navigate to system test, and start the purge vapors system test. Select open to actuate the purge solenoid to the ON position. Connect a volmeter between the evap purge control circuit and the evap purge solenoid return circuit at the PCM harness connector. The voltage supplied to the solenoid circuit during the actuation may be less than battery voltage.

Is voltage present during actuation of the purge solenoid?

YES, verify that there is good pin to terminal contact in the purge solenoid and the PCM harness connector. Replace the purge solenoid if no problems were found in the connectors.

NO, go to step 8.

Step 8. Check related PCM and component connections

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