P0443
DTC P0443, P0458, or P0459
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
DTC Descriptors
DTC P0443
- Evaporative Emission (EVAP) Purge Solenoid Control Circuit
DTC P0458
- Evaporative Emission (EVAP) Purge Solenoid Control Circuit Low Voltage
DTC P0459
- Evaporative Emission (EVAP) Purge Solenoid Control Circuit High Voltage
Diagnostic Fault Information
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
* The ignition is ON or the engine is operating.
* The engine speed is greater than 80 RPM.
* The ignition voltage is between 10-18 volts.
* The ECM has commanded the EVAP canister purge valve ON and OFF at least once during the ignition cycle.
* The DTCs run continuously once the above conditions are met.
Conditions for Setting the DTC
P0443
The ECM detects the EVAP canister purge solenoid control circuit is open. The condition exists for 4 seconds or a cumulative of 50 seconds.
P0458
The ECM detects the EVAP canister purge solenoid control circuit is shorted to ground. The condition exists for 4 seconds or a cumulative of 50 seconds.
P0459
The ECM detects the EVAP canister purge solenoid control circuit is shorted to voltage. The condition exists for 4 seconds or a cumulative of 50 seconds.
Action Taken When the DTC Sets
DTC P0443, P0458 and P0459 are Type B DTCs.
Conditions for Clearing the DTC
DTC P0443, P0458 and P0459 are Type B DTCs.
Diagnostic Aids
If the condition is intermittent, move the related harnesses and connectors, with the engine operating, while monitoring the circuit status for the component with a scan tool. The circuit status parameter changes from OK or Indeterminate to Fault if there is a condition with the circuit or a connection.
Reference Information
Schematic Reference
Engine Controls Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Evaporative Emission Control System Description (Evaporative Emission Control System Description)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Diagnostic Trouble Code Descriptions)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Verification
1. Ignition ON, command the EVAP purge solenoid to 50 percent with a scan tool. You should hear an audible click.
2. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the EVAP purge solenoid.
2. Ignition ON, verify that a test lamp illuminates between the ignition voltage circuit terminal 1 and ground.
• If the test lamp does not illuminate, test the ignition voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition voltage circuit fuse is open, test all components connected to the ignition voltage circuit and replace as necessary.
3. Connect a test lamp between the control circuit terminal 2 and the ignition voltage circuit terminal 1.
Important: The control circuit for the EVAP purge solenoid is pulled-up to voltage within the ECM, 2.6-4.6 volts on the control circuit is normal.
4. Command the EVAP purge solenoid to 50 percent and then to 0 percent with a scan tool. The test lamp should illuminate or flash and then go OFF.
• If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM.
• If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
5. Test for 2.6-4.6 volts between the control circuit terminal 2 and the ECM housing.
• If the voltage is not within the specified range, replace the ECM.
6. If all circuits test normal, test or replace the EVAP purge solenoid.
Component Testing
1. Ignition OFF, disconnect the harness connector at the EVAP purge solenoid. Test for 15-20 ohms of resistance between the terminals of the EVAP purge solenoid.
• If 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 not the specified value, replace the EVAP purge solenoid.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Evaporative Emission Canister Purge Solenoid Valve Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for ECM replacement, setup, and programming