P0443
DTC P0443
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.
DTC Descriptor
DTC P0443
- Evaporative Emission (EVAP) Purge Solenoid Control Circuit
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.
* The ignition voltage is between 11-18 volts.
* The DTCs runs continuously once the above conditions are met.
Conditions for Setting the DTC
The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match for greater than 5 seconds.
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 ([1][2]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 (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
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 the solenoid click when commanded to 50 percent.
2. Engine Idling, command the EVAP purge solenoid from 0 to 50 percent and back to 0 percent with a scan tool while observing the following control circuit status parameters:
* EVAP Purge Sol Short Gnd Test Status
* EVAP Purge Sol Open Test Status
* EVAP Purge Sol Short Volts Test Status
Each parameter should display OK or Not Run.
3. 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 a test lamp illuminates between the ignition voltage circuit terminal B 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. Test for 2.5-3.5 V between the control circuit terminal A and ground.
• If less than the specified range, test the control circuit for a short to ground or an open/high resistance. If the circuit/connections test normal, replace the ECM.
• If greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the ECM.
4. Command the EVAP purge solenoid from 0 to 100 percent with a scan tool. The DMM should transition from 2.5-3.5 V at 0 percent, to less than 0.1 V when commanded to 100 percent.
• If the circuit voltage does not correspond to the specified values, replace the ECM.
5. 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.
2. Test for 18-28 ohm between the control terminal A and the ignition voltage terminal B.
• If not within the specified range, replace the EVAP purge solenoid.
3. Test for infinite resistance between each terminal 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 engine control module replacement, setup, and programming