Diagnostic Instructions
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 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 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, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0122, P0125, P0128, P0443, P0446, P0449, P0451, P0452, P0453, P0454, P0455, P0496, P0502, P0503, 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 4-30°C (39-86°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 74 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 5 kilometers (3 miles) this trip. |
| • | The ECT is more than 70°C (158°F). |
| • | The fuel level is between 15-85 percent. |
| • | A refueling event is not detected. |
| • | The estimated ambient air temperature at the end of drive cycle is between 0-34°C (32-93°F). |
| • | 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
| • | 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 service port, 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, use the
J 41413-VLV Fitting Tool
at the service port to allow the
system to fill faster. |
| • | To help locate intermittent leaks, use the
J 41413-200 (J 41413-100) 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 using the adapters in the
J 41413-300 Kit
. |
Reference Information
Schematic Reference
Evaporative Emissions Hose Routing Diagram
Description and Operation Reference
Evaporative Emission Control System Description
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Special Tools
| • | CH 48096 EVAP Service Access Port Tool |
| • | GE 41415-50 Fuel Tank Cap Adapter |
| • | J 41413-200 (J 41413-100) Evaporative Emission System Tester (EEST) |
| • | J 41413-300 EVAP Cap and Plug Kit |
| • | J 41413-VLV EVAP Port Vent Fitting Tool |
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. |
- 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
. Connect the
J 41413-200
(J 41413-100) EEST
to the
CH 48096 Port Tool
.
- Use a scan tool to seal the system.
- Use the flow meter on the
J 41413-200 (J 41413-100) 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 (J 41413-100) EEST
to apply smoke to the EVAP system at the service port or the filler neck until the leak is located. |
Repair Instructions
Clear the DTCs with a scan tool.
Repair Verification
- Seal the system and use the flow meter on the
J 41413-200 (J 41413-100) EEST
calibrated to 0.51 mm (0.020 in) to determine that there are no leaks
in the EVAP system.
- Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.
