Diagnostic Instructions
DTC Descriptor
DTC P0442: Evaporative Emission (EVAP) System Small Leak Detected
Circuit/System Description
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 a vehicle 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 corresponding pressure changes in the fuel tank vapor space. This change is monitored by the control module using the fuel tank pressure sensor
input. The control module 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. This turbocharged engine is
equipped with a one-way flow check valve that prevents boost pressure from entering the purge line and EVAP system.
Conditions for Running the DTC
Important: The following conditions must be met prior to ignition OFF.
| • | DTCs P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0122, P0125, P0128, P0446, P0452, P0453, P0455, P0496, P0502, P0560, P0562, P0563, P0601, P0602, P0606, P0641, P2610 are not set. |
| • | The diagnostic runs once after a cold start drive cycle. |
| • | The start-up intake air temperature (IAT) is between 2-32°C (36-90°F). |
| • | The start-up engine coolant temperature (ECT) is less than 42°C (108°F). |
| • | The start-up IAT and ECT are within 9°C (16°F). |
| • | The barometric pressure (BARO) is more than 68 kPa. |
| • | The ambient air temperature is between 2-32°C (36-90°F). |
| • | The engine run time minimum is 10 minutes. |
| • | The vehicle has traveled more than 8 km (5 mi) this trip. |
| • | The shut-down ECT is more than 74°C (165°F). |
| • | The fuel level is between 12-88 percent. |
| • | 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 control module 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
(J 41413-100) Evaporative Emissions System Tester (EEST) to 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. |
| • | 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 test them one at a time. |
| • | The turbocharged engine is equipped with a one-way flow check valve that will prevent boost pressure from entering the purge line and the EVAP system. This check valve will also prevent flow from the
J 41413-200
(J 41413-100) from the purge valve into the EVAP system. |
Reference Information
Schematic Reference
Evaporative Emissions Hose Routing Diagram
Electrical Information Reference
Scan Tool Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Special Tools Required
| • | J 41413-200
Evaporative Emission System Tester (EEST) |
Circuit/System Testing
Important: Larger volume fuel tanks and/or those with lower fuel levels may require several minutes for the floating indicator to stabilize. Refer to
J 41413-200
(J 41413-100)
operation manual for detailed instructions.
- Using the
GE-41415-50
, connect the
J 41413-200
(J 41413-100) to the vehicle filler neck.
- Seal the system and use the flow meter on the
J 41413-200
(J 41413-100) 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
(J 41413-100) to apply smoke to the EVAP system at the filler neck until the leak is located. |
Repair Instructions
Important: The malfunction indicator lamp (MIL) may remain ON after the repair unless the DTCs are cleared.
