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 provide an overview of each diagnostic category.
DTC Descriptor
DTC P0443
- Evaporative Emission (EVAP) Purge Solenoid Valve Control Circuit
Diagnostic Fault Information
Circuit/System Description
An ignition voltage is supplied directly to the evaporative emission (EVAP) purge solenoid valve. The EVAP purge solenoid valve is pulse width modulated (PWM). The scan tool displays the amount of ON time as a percentage. The engine control module (ECM) monitors the status of the driver and controls the EVAP purge solenoid valve ON time by grounding the control circuit via an internal switch called a driver. If the ECM detects an incorrect voltage for the commanded state of the driver this DTC sets.
Conditions for Running the DTC
* Ignition ON.
* The system voltage is greater than 11 V.
* DTC P0443 runs continuously when 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 a minimum of 6 s.
Action Taken when the DTC Sets
DTC P0443 is a Type B DTC.
Conditions for Clearing the MIL/DTC
DTC P0443 is a Type B DTC.
Reference Information
Schematic Reference
Engine Controls Schematics (LE9) [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views Sunshade - Left (DH6)
Description and Operation
Evaporative Emission Control System Description Description and Operation
Electrical Information Reference
* Circuit Testing Circuit Testing
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
* Connector Repairs Connector Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Control Module References
Circuit/System Verification
1. Ignition ON , engine OFF, you should hear a clicking sound when the EVAP purge solenoid valve is commanded to 50 % with a scan tool. The clicking sound should stop when the EVAP purge solenoid valve is commanded to 0 %. The rate at which the valve cycles should increase when the command state is increased and decrease when the command state is decreased.
2. Engine Idling, command the EVAP purge solenoid from 0 to 50 % and back to 0 % with a scan tool while observing the following control circuit status parameters:
* EVAP Purge Solenoid Valve Control Circuit Low Voltage Test Status
* EVAP Purge Solenoid Valve Control Circuit Open Test Status
* EVAP Purge Solenoid Valve Control Circuit High Voltage 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 Q12 evaporative emission purge solenoid valve.
2. Ignition ON, verify that a test lamp illuminates between the voltage supply circuit terminal and ground.
• If the test lamp does not illuminate, test the voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and the voltage supply 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 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 K20 engine control module.
• If greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the K20 engine control module.
4. Command the EVAP purge solenoid valve from 0 to 100 % with a scan tool. The DMM should transition from 2.5-3.5 V at 0 %, to less than 0.2 V when commanded to 100 %.
• If the circuit voltage does not correspond to the specified values, replace the K20 engine control module
5. If all circuits test normal, test or replace the Q12 evaporative emission purge solenoid valve.
Component Testing
1. Ignition OFF, disconnect the harness connector at the Q12 evaporative emission purge solenoid valve.
2. Test for 10.0-30.0 ohms between the voltage supply terminal and the control circuit terminal.
• If not within the specified range, replace the Q12 evaporative emission purge solenoid valve.
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 Control Module References