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
- Evaporative Emissions (EVAP) System Small Leak Detected
Circuit/System Description
The engine off natural vacuum (EONV) 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.
* DTC P0100, P0101, P0102, P0103, P0111, P0112, P0113, P0116, P0117, P0118, P0119, P0128, P0443, P0446, P0449, P0450, P0451, P0452, P0453, P0455, P0458, P0459, P0496, P0497, P0498, P0499, P0560, P0562, P0563, P0700, P2227, P2228, or P2229 is 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 (AAT) is between 2-32°C (35-90°F).
* The engine coolant temperature (ECT) is less than 42°C (108°F) at start-up.
* The ECT and the IAT are within 10°C (18°F) of each other at engine start-up.
* The barometric pressure (BARO) is greater than 68 kPa.
* 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 6 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 MIL/DTC
DTC P0442 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 41413-200 - EEST, move all evaporative emission components while observing smoke with the J 41413-SPT - White Light.
* Individual components can be isolated and tested using adapters in the J 41413-300 - 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
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Evaporative Emission Control System Description (Evaporative Emission Control System Description)
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 41413-SPT - High Intensity White Light
* J 41413-VLV - EVAP Port Vent Fitting Tool
* J 41413-200 - Evaporative Emissions System Tester (EEST)
* J 41413-300 - EVAP Cap and Plug Kit
* For equivalent regional tools, refer to Special Tools (Tools and Equipment).
Circuit/System Testing
Note:
* Refer to the J 41413-200 - EEST operation manual for detailed instructions in Evaporative Emission System Diagnosis (Evaporative Emission System Diagnosis).
* Larger volume fuel tanks and/or those with lower fuel levels may require several min 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 canister purge solenoid valve and install the CH 48096 - Port Tool.
2. Connect the J 41413-200 - EEST to the CH 48096 - Port Tool.
3. Using a scan tool close the evaporative emission canister vent solenoid valve to seal the evaporative emission system.
4. Use the flow meter on the J 41413-200 - EEST, 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 41413-200 - EEST to apply smoke to the evaporative emission system at the purge tube until the leak is located using the J 41413-SPT - White Light.
Repair Verification
1. Seal the EVAP system and use the flow meter on the J 41413-200 - EEST, calibrated to 0.51 mm (0.020 in) to verify there is no leak in the EVAP system.
2. Clear DTCs.