P0442
DTC P0442
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 P0442 00
- Evaporative Emission (EVAP) System Small Leak Detected
Circuit/System Description
The engine off natural vacuum test is the small leak detection diagnostic for the evaporative emission system. This diagnostic tests the Evaporative Emission (EVAP) system for a small leak when the key is turned OFF and the correct conditions are met. Heat from the exhaust system is transferred into the fuel tank while the vehicle is operating. When the vehicle is turned OFF and the EVAP system is sealed a change in the fuel tank vapor temperature occurs which results in a corresponding pressure change in the fuel tank vapor space. This change is monitored by the engine control module (ECM) using the fuel tank pressure sensor input. With a leak in the system, the amount of pressure change will be less than that of a sealed system.
Conditions for Running the DTC
Note: The following conditions must be met prior to ignition OFF.
* DTCs P0100 00, P0101 00, P0102 00, P0103 00, P0111 00, P0112 00, P0113 00, P0116 00, P0117 00, P0118 00, P0119 00, P0128 00, P0443 00, P0446 00, P0449 00, P0451 00, P0452 00, P0453 00, P0455 00, P0496 00, P0560 00, P0562 00, P0563 00, P0700 00, P2227 00, P2228 00, or P2229 00 are not set.
* The ignition voltage is greater than 11 V.
* A refueling event is not detected.
* The EVAP purge solenoid valve command is less than 26%.
* The engine coolant temperature (ECT) during the previous ignition was greater than 74°C (165°F).
* The ambient air temperature is between 2-32°C (35-90°F).
* The engine coolant temperature (ECT) is less than 42°C (108°F) at start up.
* The Engine Coolant Temperature and the Intake Air Temperature are within 10°C (18°F) of each other at engine start up.
* The barometric pressure (BARO) is greater than 68 kPa (9.8 PSI).
* The vehicle has traveled greater than 5 km (3 mi) this trip.
* The fuel level is between 11-88%.
* The vehicle traveled greater than 8 km (5 mi).
* The engine run time is greater than 10 min.
* DTC P0442 00 runs once per engine off cycle when the above conditions have been met prior to engine shut down.
Conditions for Setting the DTC
The control module detects approximately vacuum/pressure changes significantly less than a calibrated amount. The condition exists during the engine OFF test, then a 5 s delay for the MIL after engine start up.
Action Taken When the DTC Sets
DTC P0442 00 is a Type A DTC.
Conditions for Clearing the DTC
DTC P0442 00 is a Type A DTC.
Diagnostic Aids
* The evaporative emission system can be filled with smoke more quickly and completely by opening the system opposite the end where the smoke is injected. When injecting smoke at the service port remove the fuel fill cap, or temporarily leave the vent open, until smoke is observed then close the system and continue testing.
* To help locate intermittent leaks using the J 4143-100 - Evaporative Emissions System Tester , move all evaporative emission components while observing smoke with the J 4143-SPT - High Intensity White Light.
* Individual components can be isolated and tested using adapters in the J 4143-300 - EVAP Cap And Plug Kit.
* A condition may exist where a leak in the evaporative emission system only exists under a vacuum condition. This type of leak may be detected by using the scan tool Purge/Seal function to create a vacuum in the evaporative emission system and then observe the fuel tank pressure parameter for vacuum decay.
Reference Information
Schematic Reference
Engine Controls Schematics ([1][2]Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
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
Special Tools
* CH 48096 - EVAP Service Port Access Tool
* J 4143-100 - Evaporative Emissions System Tester
* J 4143-200 - Evaporative Emissions System Tester
* J 4143-300 - EVAP Cap And Plug Kit
* J 4143-VLV - EVAP Port Vent Fitting Tool
* J 4143-SPT - High Intensity White Light
* For equivalent regional tools, refer to Special Tools (Tools and Equipment).
Circuit/System Verification
Note:
* Refer to the J 4143-200 - Evaporative Emissions System Tester operation manual for detailed instructions in
* Larger volume fuel tanks and/or those with lower fuel levels may require several minutes for the floating indicator to stabilize.
* Ensure that the underbody temperature of the vehicle and the tester are similar.
1. Disconnect the purge tube at the quick connector on the evaporative emission canister side of the Q12 Evaporative Emission Purge Solenoid Valve and install the CH 48096 - EVAP Service Port Access
Tool.
2. Connect the J 4143-200 - Evaporative Emissions System Tester to the CH 48096 - EVAP Service Port Access Tool.
3. Using a scan tool close the Q13 Evaporative Emission Vent Solenoid Valve to seal the evaporative emission system.
4. Use the flow meter on the J 4143-200 - Evaporative Emissions System Tester , calibrated to 0.51 mm (0.020 in) to determine that there is no leak in the evaporative emission system.
• If a leak is detected, use the J 4143-200 - Evaporative Emissions System Tester to apply smoke to the evaporative emission system at the purge tube until the leak is located using the J 4143-SPT - High Intensity White Light.
Repair Verification
1. Seal the EVAP system and use the flow meter on the J 4143-200 - Evaporative Emissions System Tester , calibrated to 0.51 mm (0.020 in) to verify there is no leak in the EVAP system.
2. Clear DTCs.