GM Service Manual Online
For 1990-2009 cars only

Description

The evaporative emission (EVAP) Service Bay Test raises the engine coolant temperature (ECT) threshold so that the temperature sensitive EVAP diagnosis tests can run while in service environments. When the EVAP tests are run the Service Bay Test will indicate a passed or that a specific diagnostic trouble code (DTC) code has failed. The EVAP Service Bay Test can be used to verify an existing condition and verify that the EVAP system is OK after a repair is 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 9.0-18.0 volts.
    • The ECT is less than 70°C (158°F).
    • The fuel level is 15-85 percent of capacity.
    • The vehicle speed is less than 2 km/h (3 mph).
    • Any stored DTCs have been cleared.

Test Procedure

  1. Connect a scan tool.
  2. Use the scan tool in order to select the Service Bay Test in the Special Functions menu.
  3. Follow the instructions on the scan tool.
  4. Continue with the published service manual diagnostic DTC procedure.