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 provides an overview of each diagnostic category.
DTC Descriptor
DTC P0442
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Evaporative Emission (EVAP) System Small Leak Detected
Circuit/System Description
This DTC tests the evaporative emission (EVAP) system for a small leak. The engine control module (ECM) monitors the fuel tank pressure sensor signal to determine the vacuum decay rate. At an appropriate time, the ECM turns the EVAP canister purge solenoid valve ON and the EVAP vent solenoid valve ON. This allows the engine to draw a vacuum on the EVAP system. At a calibrated time, or vacuum level, the ECM turns the EVAP canister purge solenoid valve OFF, sealing the system, and monitors the fuel tank pressure sensor input in order to determine the EVAP system vacuum decay. If the ECM detects a leak larger than a calibrated amount, these DTCs will set.
Conditions for Running the DTC
Note:
The following conditions must be met prior to ignition OFF.
* DTC P0101, P0102, P0103, P0111, P0112, P0113, P0116, P0117, P0118, P0119, P0128, P0443, P0446, P0449, P0451, P0452, P0453, P0455, P0496, P0562, P0563, P0700, P2227, P2228, P2229 or P2610 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 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 is a Type A DTC.
Conditions for Clearing the DTC
DTC P0442 is a Type A DTC.
Diagnostic Aids
* The EVAP system can be filled with smoke more quickly and completely by opening the system opposite the end where the smoke is injected. For example, when injecting smoke at the purge tube, remove the filler cap or temporarily leave the vent open until smoke is observed. Close the system and continue testing. If using a fuel cap adapter at the filler neck, disconnect the purge tube at the EVAP canister purge solenoid valve until smoke is observed.
* To help locate intermittent leaks, use the EN 41413-200 - emissions system testerto introduce smoke into the EVAP system. Move all EVAP components while observing smoke with a high intensity white light.
* To improve the visibility of the smoke exiting the EVAP system, observe the suspected leak area from different angles with a high intensity white light.
* If a small leak is difficult to find, it may be necessary to remove the EVAP components and test them one at a time using the adapters in the EN 41413-300 - EVAP cap and plug kit.
Reference Information
Schematic Reference
Engine Controls Schematics [1][2]Electrical Diagrams
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
Special Tools
CH 48096 - EVAP Service Access Port Tool
EN 41413-SPT - High Intensity White Light
EN 41413-200 - Emissions System Tester
EN 41413-300 - EVAP Cap and Plug Kit
For equivalent regional tools, refer to Special Tools Tools and Equipment.
Circuit/System Testing
* Larger volume fuel tanks and/or those with lower fuel levels may require several minutes for the floating indicator to stabilize.
* Ensure that the vehicle underbody temperature is similar to the ambient temperature and allow the surrounding air to stabilize before starting the diagnostic procedure. The system flow will be less with higher temperatures.
* Refer to the EN 41413-200 - emissions system testeroperation manual for detailed instructions.
1. Connect the EN 41413-200 - emissions system testerto the vehicle at the EVAP service port. For vehicles without a service port, disconnect the purge tube at the quick connector on the EVAP canister side of the Q12 Evaporative Emission Purge Solenoid Valve and install the CH 48096 - EVAP service access port tool.
2. Using a scan tool, close the Q13 Evaporative Emission Vent Solenoid Valve to seal the EVAP system.
3. Use the flow meter on the EN 41413-200 - emissions system tester, calibrated to 0.51 mm (0.02 in) to determine that there is no leak in the EVAP system.
• If a leak is detected, use the EN 41413-200 - emissions system testerto apply smoke to the EVAP system at the service port or the purge tube until the leak is located using the EN 41413-SPT - high intensity white light.
Repair Instructions
1. Seal the EVAP system and use the flow meter on the EN 41413-200 - emissions system tester, calibrated to 0.51 mm (0.02 in) to determine that there is no leak in the EVAP system.
2. Clear DTCs.