P0442

DTC P0442

SYSTEM DESCRIPTION
The evaporative emission (EVAP) small leak test applies vacuum to the EVAP system and monitors vacuum decay. The control module monitors the fuel tank pressure sensor signal to determine the vacuum decay rate. At an appropriate time, the EVAP canister purge solenoid valve and the EVAP vent valve are turned ON. This allows the engine to draw vacuum on the EVAP system. After the desired vacuum level has been achieved, the EVAP purge valve is turned OFF, sealing the system. A leak is detected by monitoring for a decrease in vacuum level during a given time period. If the system detects a leak larger than a calibrated amount, DTC P0442 will set.

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC P0442 Evaporative Emission (EVAP) System Small Leak Detected

CONDITIONS FOR RUNNING THE DTC
- DTCs P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0222, P0223, P0443, P0446, P0449, P0452, P0453, P0455, P0461, P0462, P0463, P0496, P0608, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138 are not set.
- 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 fuel level is between 15-85 percent.
- DTC P0442 runs once per cold start.

CONDITIONS FOR SETTING THE DTC
- The control module detects a pressure change that is greater than a calibrated amount.
- A minimum of 3 tests must be completed for the diagnostic to report a fail. Each of the 3 tests must begin with a cold start where all of the Conditions for Running the DTC have been met. Each test can take up to 17 minutes to complete.

ACTION TAKEN WHEN THE DTC SETS
- The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
- The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
- The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
- A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
- A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
- Clear the MIL and the DTC with a scan tool.

DIAGNOSTIC AIDS
- To help locate intermittent leaks, use the J 41413-200 evaporative emissions system tester (EEST) to introduce smoke into the EVAP system. Move all EVAP components while observing smoke with the J 41413-SPT 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 fuel tank pressure (FTP) parameter for vacuum decay, this type of leak may be detected.
- To improve the visibility of the smoke exiting the EVAP system, observe the suspected leak area from different angles with the J 41413-SPT.
- For intermittent conditions, refer to Testing for Intermittent Conditions and Poor Connections. Component Tests and General Diagnostics

TEST DESCRIPTION

Step 1 - Step 4:

Step 5 - Step 7:

The numbers below refer to the step numbers on the diagnostic table.
3. Introducing smoke in 15 second intervals may allow smaller leak areas to be more noticeable. When the system is less pressurized, the smoke will sometimes escape in a more condensed manner.
5. This step verifies that repairs are complete and that no other condition is present.