P0442
DTC P0442
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview)provide an overview of each diagnostic category.
DTC Descriptor
DTC P0442
- Evaporative Emissions (EVAP) System Small Leak Detected
Circuit/System Description
This diagnostic tests the evaporative emission (EVAP) system for a small leak when the ignition is turned OFF and the correct conditions are met. Heat is transferred from operating the vehicle and ambient conditions into a vehicle fuel tank during normal operation. When the ignition is turned OFF and the EVAP system is sealed, a change in the fuel tank vapor temperature occurs, which results in corresponding pressure changes in the fuel tank vapor space. This change is monitored by the engine control module (ECM) using the fuel tank pressure sensor input. The ECM then makes a judgment on the integrity of the system. With a 0.51 mm (0.02 in) leak in the system, the amount of pressure change observed is significantly less than that of a sealed system.
Conditions for Running the DTC
Note: The following conditions must be met prior to ignition OFF.
* DTCs P0101, P0102, P0103, P0111, P0112, P0113, P0116, P0117, P0118, P0122, P0125, P0128, P0443, P0446, P0449, P0452, P0453, P0455, P0461, P0462, P0463, P0496, P0502, P0503, P2066, P2067, P2068, P2610 are not set.
* The diagnostic runs once after a cold start drive cycle.
* The start-up intake air temperature (IAT) is between 0-34°C (32-93°F).
* The start-up engine coolant temperature (ECT) is less than 30°C (86°F).
* The start-up IAT and ECT are within 8°C (15°F).
* The barometric pressure (BARO) is more than 70 kPa.
* The ambient air temperature is between 0-34°C (32-93°F).
* The engine run time minimum is 10 minutes.
* The vehicle has traveled more than 5 kilometers (3 miles) this trip.
* The ECT is more than 70°C (158°F).
* The fuel level is between 10-905 percent.
* The ignition is OFF.
* A refueling event is not detected.
* DTC P0442 runs once per drive cycle when the above conditions are met.
* One test occurs at ignition OFF after a drive cycle, and may require up to 45 minutes to complete. No more than 2 tests per day are allowed.
Conditions for Setting the DTC
* The ECM detects a pressure change that is less than a calibrated amount.
* Several tests must be completed to report a Fail with up to 17 hours between tests.
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
* To help locate intermittent leaks, use the J 41413-200 - EEST to introduce smoke into the EVAP system. Move all EVAP components while observing smoke with the J 41413-SPT - Light.
* To improve the visibility of the smoke exiting the EVAP system, observe the suspected leak area from different angles with the J 41413-SPT - Light.
* A condition may exist where a leak in the EVAP system only exists under a vacuum condition. By using the scan tool Purge/Seal function to create a vacuum, seal the system and observe the FTP parameter for vacuum decay, this type of leak may be detected.
* If a small leak is difficult to find, it may be necessary to remove the EVAP components and leak test them one at a time using the adapters in the J 41413-300 - Kit.
Reference Information
Schematic Reference
Evaporative Emissions Hose Routing Diagram (Evaporative Emissions Hose Routing Diagram)
Description and Operation
Evaporative Emission Control System Description (Evaporative Emission Control System Description)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Diagnostic Trouble Code Descriptions)
Scan Tool Reference
Control Module References (Programming and Relearning)for scan tool information
Special Tools
* CH 48096 - EVAP Service Access Port Tool
* GE 41415-50 - Fuel Tank Cap Adapter
* J 41413-200 - Evaporative Emission System Tester (EEST)
* J 41413-300 - EVAP Cap and Plug Kit
* J 41413-311 - EVAP Plug
* J 41413-SPT - High Intensity White Light
Circuit/System Testing
Note:
* Larger volume fuel tanks and/or those with lower fuel levels may require several minutes for the floating indicator to stabilize.
* Refer to the J 41413-200 - EEST operation manual for detailed instructions in Evaporative Emission System Diagnosis (Evaporative Emission System Diagnosis)
1. Connect the J 41413-200 - EEST nitrogen/smoke hose to the J 41413-311 - EVAP Plug brass cone adapter. Disconnect the hose at the fuel cap end of the GE 41415-50 - Adapter. Connect the J 41413-311 - EVAP Plug to the disconnected hose on the GE 41415-50 - Adapter. Install the GE 41415-50 - Adapter filler neck end only to the vehicle. For vehicles without a service port, disconnect the purge tube at the quick connector on the EVAP canister side of the EVAP canister purge solenoid valve and install the CH 48096 - Port Tool.
2. Seal the system and 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 EVAP system.
• If a leak is detected use the J 41413-200 - EEST to apply smoke to the EVAP system at the service port or the filler neck until the leak is located. For vehicles without a service port, disconnect the purge tube at the quick connector on the EVAP canister side of the purge solenoid valve and install the CH 48096 - Port Tool.
Repair Instructions
1. The malfunction indicator lamp (MIL) may remain ON after the repair unless the DTCs are cleared.
2. Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.