GM Service Manual Online
For 1990-2009 cars only

Description

The evaporative emission (EVAP) Service Bay Test is designed to hasten the resetting of the EVAP inspection/maintenance (I/M) system status to Complete. The Service Bay Test uses the scan tool to initiate the control modules regular sequence of the EVAP system DTC tests. The Service Bay Test only activates the regular DTC test, but with relaxed temperature thresholds. The scan tool will display any specific reasons the test aborts or if the tests have passed or failed. The test will not begin if any enabling criteria are not met. On vehicles equipped with engine off natural vacuum (EONV), the time that is required for resetting the I/M system status to Complete is minimized by eliminating multiple cold soaks. The Service Bay Test can be used to verify that the EVAP system is OK after a repair has been completed.

Conditions for Running the Test

Important: The following conditions must be met in order to enable the Service Bay Test:

    • The ignition is ON.
    • The battery voltage is between 9-18 volts.
    • The engine coolant temperature (ECT) is less than 70°C (158°F).
    • The fuel level is 15-85 percent of capacity.
    • The vehicle speed is less than 4.8 km/h (3 mph).
    • Stored DTCs have been cleared.

Diagnostic Aids

Vehicles equipped with the EONV diagnostic should refer to Evaporative Emission Control System Description .

Use the Evaporative Emissions System Tester J 41413-200 with the Operation Manual J 41413-210 to locate any EVAP leaks.

Test Procedure

  1. Install a scan tool.
  2. With a scan tool, select the service bay test in the special functions menu.
  3. Follow the instructions on the scan tool.
  4. Check DTCs with a scan tool.
  5. Continue with the published service manual diagnostic DTC procedure.