GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Classic 🢒 Engine 🢒 Engine Controls - 2.2L (L61) 🢒 DTC P0442

System Description

This DTC tests the evaporative emission (EVAP) system for a small leak. The control module monitors the fuel tank pressure (FTP) sensor signal to determine the vacuum decay rate. At an appropriate time, the control module turns the EVAP canister purge solenoid valve ON and the EVAP vent solenoid valve ON. This allows the engine to draw a vacuum on the EVAP system. At a calibrated time, or vacuum level, the control module turns the EVAP canister purge solenoid valve OFF, sealing the system, and monitors the FTP sensor input in order to determine the EVAP system vacuum decay. If the control module detects a leak larger than a calibrated amount, this DTC sets.

The following table illustrates the relationship between the ON and OFF states, and the Open or Closed states of the EVAP canister purge and vent solenoid valves.

Control Module Command

EVAP Canister Purge Solenoid Valve

EVAP Canister Vent Solenoid Valve

ON

Open

Closed

OFF

Closed

Open

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0442 Evaporative Emission (EVAP) System Small Leak

Conditions for Running the DTC
    • Before the powertrain control module (PCM) can report DTC P0442 failed, DTCs P0446, P0452, P0453, P0455, and P0496 must run and pass.
    • DTCs P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0122, P0123, P0125, P0128, P0130, P0131, P0132, P0133, P0134, P0135, P0452, P0453, P0502, P0601, P0602, P1133, and P1621 are not set.
    • The ignition voltage is between 11-18 volts.
    • The barometric pressure (BARO) is more than 75 kPa.
    • The fuel level is between 15-85 percent.
    • The start-up engine coolant temperature (ECT) is between 4-30°C (39-86°F).
    • The start-up intake air temperature (IAT) is between 4-30°C (39-86°F).
    • The start-up ECT and IAT are within 9°C (16°F) of each other.
    • The vehicle speed sensor (VSS) is less than 137 km/h (85 mph).
    • The purge solenoid valve is enabled.
    • The throttle position is between 7-35 percent.
    • The small leak diagnostic test runs once per cold start drive cycle.

Conditions for Setting the DTC

The EVAP system can achieve vacuum but a vacuum decay is detected during the diagnostic test.

A minimum of 3 tests must fail for the PCM to report a fail. Each test may take up to 5 minutes 30 seconds.

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 J 41413-200 Evaporative Emissions System Tester (EEST) to introduce smoke into the EVAP system. Move all EVAP components while observing smoke with J 41413-SPT High Intensity White 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 .
    • A leak in the EVAP system can be verified by the use of the flow meter on J 41413-200 . Refer to J 41413-200 operation manual for flow meter use.
    • For intermittent conditions, 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 - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2
  1. Inspect the evaporative emission (EVAP) system for the following conditions:
    2. • A loose, missing, or damaged service port dust cap and/or schrader valve
    • A loose, incorrect, missing, or damaged fuel fill cap
    • A damaged EVAP purge solenoid valve
  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. • Any disconnected, improperly routed, kinked, or damaged EVAP pipes and hose
    • A damaged EVAP vent solenoid valve or EVAP canister

Did you find and correct the condition?

Go to Step 5

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.

    Important: Refer to J 41413-200 Evaporative Emissions System Tester (EEST) operation manual for detailed instructions.

  1. Turn OFF the ignition.
  2. Using J 41415-40 Fuel Tank Cap Adapter connect J 41413-200 to the vehicle filler neck.
  3. Turn ON the ignition, with the engine OFF.
  4. Seal the system and apply smoke to the system until smoke is visible atJ 41413-VLV EVAP Service Port Vent Fitting. Continue to apply smoke for an additional 60 seconds.
  5. Inspect the entire EVAP system for exiting smoke with the J 41413-SPT High Intensity White Light.
  6. 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 5

Go to Step 4

4
  1. Disconnect the J 41415-40 from the fuel fill pipe.
  2. Install the fuel fill cap to the fuel fill pipe.
  3. Connect the J 41413-200 nitrogen/smoke supply hose to the EVAP service port.
  4. Use the remote switch to introduce smoke into the EVAP system.
  5. Inspect the entire EVAP system for exiting smoke with the J 41413-SPT .
  6. 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 5

Go to Diagnostic Aids

5

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

  1. Use the flow meter on J 41413-200 to determine if there is a leak greater than 0.51 mm (0.020 in) in the EVAP system.
  2. Compare the flow meter stable floating indicator position to the red flag.

Is the floating indicator below the red flag?

Go to Step 6

Go to Step 2

6

Observe the Capture Info with a scan tool.

Have any other DTCs not been diagnosed?

Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information

Go to Step 7

7

Important: The malfunction indicator lamp (MIL) may remain ON after the repair unless the DTCs are cleared.

Clear the DTCs with a scan tool.

Did you complete the action?

System OK

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