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 Valve Control Circuit
Diagnostic Fault Information
Circuit/System Description
An ignition voltage is supplied directly to the evaporative emission (EVAP) purge solenoid valve. The engine control module (ECM) grounds the EVAP purge solenoid valve control circuit through an internal switch called a driver. The ECM monitors the status of the driver. The EVAP purge solenoid valve is pulse width modulated (PWM). A scan tool will display the amount of ON time as a percentage. If the ECM detects an incorrect voltage for the commanded state of the driver this DTC sets.
Conditions for Running the DTC
* 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 0.25 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 [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views Fuel Pump and Level Sensor Assembly
Description and Operation
Evaporative Emission Control System Description Description and Operation
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 Control Module References for scan tool information
Circuit/System Verification
1. Ignition ON.
2. Verify the parameters listed below do not display malfunction when commanding the EVAP purge solenoid valve from 0 to 50 % and back to 0 % with a scan tool.
* 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
• If Malfunction is displayed
Refer to Circuit/System Testing
• If Malfunction is not display
3. All OK.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the Q12 Evaporative Emission Purge Solenoid Valve, ignition ON.
2. Verify that a test lamp illuminates between the ignition circuit terminal 2 and ground.
• If the test lamp does not illuminate and the circuit fuse is good
1. Ignition OFF, remove the test lamp.
2. Test for less than 2 ohms in the ignition circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms verify the fuse is not open and there is voltage at the fuse.
• If the test lamp does not illuminate and the circuit fuse is open
1. Ignition OFF, remove the test lamp.
2. Test for infinite resistance between the ignition circuit and ground.
• If less than infinite resistance, repair the short to ground in the circuit.
• If infinite resistance, test the Q12 Evaporative Emission Purge Solenoid Valve and replace as necessary.
• If the test lamp illuminates
3. Verify that a test lamp does not illuminate between the ignition circuit terminal 2 and the control circuit terminal 1.
• If the test lamp illuminates
1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
2. Test for infinite resistance between the control circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the K20 Engine Control Module.
• If the test lamp does not illuminate
4. Remove the test lamp.
5. Verify the scan tool EVAP Purge Solenoid Valve Control Circuit High Voltage Test Status parameter is OK when commanding the EVAP purge solenoid valve ON with a scan tool.
• If the Parameter is not OK
1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON.
2. Test for less than 1 V between the control circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K20 Engine Control Module.
• If the Parameter is OK
6. Install a 3 A fused jumper wire between the control circuit terminal 1 and the ignition circuit terminal 2.
7. Verify the scan tool EVAP Purge Solenoid Valve Control Circuit High Voltage Test Status parameter is Malfunction when commanding the EVAP Purge Solenoid Valve ON with a scan tool.
• If the Parameter is not Malfunction.
1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
2. Test for less than 2 ohms in the control circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms replace the K20 Engine Control Module.
• If the parameter is Malfunction
8. Test or replace the Q12 Evaporative Emission Purge Solenoid Valve.
Component Testing
Static Test
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 control circuit terminal 1 and the ignition circuit terminal 2 of the Q12 Evaporative Emission Purge Solenoid Valve.
• If not between 10.0-30.0 ohms
Replace the Q12 Evaporative Emission Purge Solenoid Valve
• If between 10.0-30.0 ohms
3. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Evaporative Emission Canister Purge Solenoid Valve Replacement Service and Repair
* Control Module References Control Module References for ECM replacement, setup, and programming