GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Saturn 🢒 2004 🢒 VUE - AWD 🢒 DTC 🢒 DTC P0442

System Description

The DTC P0442 Evaporative Emission (EVAP) System Leak Detected diagnostic monitors the EVAP system for a small leak. The diagnostic runs when the ignition is in the OFF position, and the correct conditions are met . While the vehicle is operating, there are sources of heat transferred into the tank from the following:

    • Exhaust heat
    • Engine heat
    • Ambient temperature

When the engine is stopped and the ignition is in the OFF position a change in the fuel tank vapor temperature occurs. This results in a change in the pressure of the fuel tank vapor space. This change in pressure is monitored by the control module , using the fuel tank pressure (FTP) sensor input. The EVAP diagnostic detects leaks as small as 0.51 mm (0.020 in). If the control module detects a change in the fuel tank vacuum/pressure less than a calibrated amount, this DTC sets.

DTC Descriptor

This diagnostic supports the following DTC.

DTC  P0442 Evaporative Emissions (EVAP) System Small Leak Detected

Conditions for Running the DTC

Important: The following conditions must be met prior to ignition OFF.

    • Before the PCM can report DTC P0442 failed, DTCs P0455, and P2199 must run and pass.
    • DTCs P0107, P0108, P0117, P0118, P0452, P0453, P0496, P0498, P0499 , P1128, P1129, P2227, P2228, and P2229 are not set.
    • A refueling event is not detected.
    • The fuel volatility is not excessive.
    • The ambient air temperature is 4°C (40°F) or above.
    • The engine coolant temperature is more than 69°C (156°F).
    • The fuel level is between 15 and 85 percent.
    • The engine run time is more than 25 minutes.
    • DTC P0442 runs once per drive cycle when the above conditions are met.

Conditions for Setting the DTC

The control module detects a vacuum/pressure change that is less than the calibrated amount.

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 an intermittent leak, 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. Introducing smoke in 15 second intervals will allow less pressure into the EVAP system. When the system is less pressurized, the smoke will sometimes escape in a more condensed manner.
    • To improve the visibility of the smoke exiting the EVAP system, observe the suspected leak area from different angles with the J 41413-SPT High Intensity White Light.
    • For an intermittent condition, refer to Intermittent Conditions .

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. 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.

  2. This step verifies that repairs are complete and that no other condition is present.

Step

Action

Yes

No

Schematic Reference: Evaporative Emissions Hose Routing Diagram

1

Did you perform the Diagnostic System Check-Engine Controls?

Go to Step 2

Go to Diagnostic System Check - Engine Controls

2
  1. Inspect the evaporative emission (EVAP) system for the following conditions:
    2. • Loose, missing, or damaged service port dust cap and/or schrader valve
    • Loose, incorrect, missing, or damaged fuel fill cap
    • A damaged EVAP purge solenoid
  2. Raise the vehicle on a hoist. Refer to Lifting and Jacking the Vehicle in General Information.
  3. Inspect the EVAP system for the following conditions:
    4. • Disconnected, improperly routed, kinked, or damaged EVAP pipes and hose
    • A damaged EVAP vent valve or EVAP canister

Did you find and correct the condition?

Go to Step 4

Go to Step 3

3

Important: Ensure that the vehicle underbody temperature is similar to the ambient temperature and allow the surrounding air to stabilize before starting the diagnostic procedure. System flow will be less with higher temperatures.

  1. Turn OFF the ignition.
  2. Connect the J 41413-200 Evaporative Emissions System Tester (EEST) power supply clips to a known good 12-volt source.

    3. Important: The GE-41415-50 fuel cap adapter, may not be available for the start of production. Once the J41415-50 is available, start the diagnosis at the fuel fill cap.

  3. Install the nitrogen/smoke supply hose onto one of the following sources:
    4. • Connect the GE-41415-50 to the fuel fill pipe, and the J 41413-200 nitrogen/smoke supply hose to the fuel cap adapter.
    • Connect the J 41413-200 nitrogen/smoke supply hose to the EVAP service port.
  4. Turn ON the ignition with the engine OFF.
  5. Command the EVAP vent valve closed with a scan tool.
  6. Turn the nitrogen/smoke valve on the J 41413-200 control panel to SMOKE.
  7. Use the remote switch to introduce smoke into the EVAP system for 60 seconds.
  8. Inspect the entire EVAP system for exiting smoke with the J 41413-SPT High Intensity White Light.
  9. Continue to introduce smoke at 15 second intervals until the leak source has been located.

Did you locate and repair a leak source?

Go to Step 4

Go to Diagnostic Aids

4

Important: Larger volume fuel tanks and/or those with lower fuel levels may require several minutes for the floating indicator to stabilize.

  1. Turn the nitrogen/smoke valve to nitrogen.
  2. Connect the nitrogen/smoke hose to the 0.5 mm (0.020 in) test orifice on the bottom-front of the J 41413-200 .
  3. Use the remote switch to activate the J 41413-200 .
  4. Align the red flag on the flow meter with the floating indicator. Use the remote switch to de-activate the J 41413-200 .
  5. Remove the nitrogen/smoke hose from the test orifice.

    6. Important: The GE-41415-50 fuel cap adapter, may not be available for the start of production. Once the J41415-50 is available, start the diagnosis at the fuel fill cap.

  6. Install the nitrogen/smoke supply hose onto one of the following sources:
    7. • Connect the GE-41415-50 to the fuel fill pipe, and the J 41413-200 nitrogen/smoke supply hose to the fuel cap adapter.
    • Connect the J 41413-200 nitrogen/smoke supply hose to the EVAP service port.
  7. Turn ON the ignition, with the engine OFF.
  8. Command the EVAP vent solenoid closed with a scan tool.
  9. Use the remote switch to introduce nitrogen and fill the EVAP system until the floating stabilizes.
  10. Compare the flow meter's stable floating indicator position to the red flag.

Is the floating indicator below the red flag?

Go to Step 5

Go to Step 2

5

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

Go to Diagnostic Trouble Code (DTC) List

System OK