P0443

DTC P0443

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Strategy Based Diagnosis Strategy Based Diagnosis
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions

DTC Descriptor
DTC P0443
- Evaporative Emission (EVAP) Purge Solenoid Control Circuit

Circuit/System Description

The evaporative emission (EVAP) canister purge valve is used to purge fuel vapor from the EVAP canister to the intake manifold. The EVAP canister purge valve is pulse width modulated (PWM). Ignition voltage is supplied directly to the EVAP canister purge valve. The engine control module (ECM) controls the solenoid by grounding the control circuit with a solid state device called a driver. The driver is equipped with a feedback circuit that is pulled-up to a voltage. The ECM can determine if the control circuit is open, shorted to ground, or shorted to a voltage by monitoring the feedback voltage.

Conditions for Running the DTC

* DTC P0606 is not set for Euro IV emissions only.
* The ignition is ON.
* The ignition voltage is greater than 11 volts.
* The DTC runs continuously once the above conditions are met.

Conditions for Setting the DTC

The ECM detects the EVAP purge solenoid control circuit is open, shorted to ground, or shorted to voltage.

Action Taken When the DTC Sets

DTC P0443 is a Type B DTC.

Conditions for Clearing the DTC

DTC P0443 is a Type B DTC.

Reference Information

Schematic Reference

Engine Controls Schematics (w/Throttle Actuator Controls) Electrical DiagramsEngine Controls Schematics (w/o Throttle Actuator Control) Electrical Diagrams

Connector End View Reference
* Engine Control Module Connector End Views (w/ Throttle Actuator Control) Engine Control Module Connector End Views (w/ Throttle Actuator Control)Engine Control Module Connector End Views (w/o Throttle Actuator Control) Engine Control Module Connector End Views (w/o Throttle Actuator Control)
* Engine Controls Connector End Views (w/ Throttle Actuator Control) Engine Controls Connector End Views (w/ Throttle Actuator Control)Engine Controls Connector End Views (w/o Throttle Actuator Control) Engine Controls Connector End Views (w/o Throttle Actuator Control)

Description and Operation

Evaporative Emission Control System Description Evaporative Emission Control System Description

Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference
* Scan Tool Data List (w/ Throttle Actuator Control) Scan Tool Data List (w/ Throttle Actuator Control)Scan Tool Data List (w/o Throttle Actuator Control) Scan Tool Data List (w/o Throttle Actuator Control)
* Scan Tool Data Definitions (w/ Throttle Actuator Control) Scan Tool Data Definitions (w/ Throttle Actuator Control)Scan Tool Data Definitions (w/o Throttle Actuator Control) Scan Tool Data Definitions (w/o Throttle Actuator Control)
* Scan Tool Output Controls (w/ Throttle Actuator Control) Scan Tool Output Controls (w/ Throttle Actuator Control)Scan Tool Output Controls (w/o Throttle Actuator Control) Scan Tool Output Controls (w/o Throttle Actuator Control)

Circuit/System Verification

With a scan tool, command the EVAP Purge Solenoid ON and OFF. You should hear the solenoid click when commanded ON and OFF.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector of the EVAP purge solenoid.
2. Ignition ON, verify a test lamp illuminates between the ignition 1 voltage circuit and ground.

• If the test lamp does not illuminate, test the ignition 1 voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition 1 voltage circuit fuse is open, test all components connected to the ignition 1 voltage circuit and replace as necessary.

3. Ignition OFF, connect a test lamp between the control circuit and the ignition 1 voltage.
4. Ignition ON, with a scan tool, command the EVAP Purge Solenoid to 100 percent, and back to 0 percent. The test lamp should respond to the commanded state.

• If the test lamp remains ON all the time, test for a short to ground on the control circuit. If circuit/connections test normal, replace the ECM.

• If the test lamp remains OFF all the time, test for a short to voltage or an open/high resistance on the control circuit. If circuit/connections test normal, replace the ECM.

5. If all circuits/connections test normal, test or replace the EVAP purge solenoid.

Component Testing

1. Measure for 18-28 ohms of resistance between the terminals of the EVAP purge solenoid.

• If the resistance is not within the specified range, replace the EVAP purge solenoid.

2. Test for infinite resistance between each terminal of the EVAP purge solenoid and the EVAP purge solenoid housing.

• If less than infinite resistance, replace the EVAP purge solenoid.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

* Evaporative Emission Canister Replacement Service and Repair
* Control Module References Control Module References for engine control module replacement, setup, and programming