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Home >> Volkswagen >> 2021 >> Atlas S, AWD >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Generic Scan Tool (CDVC) (Diagnosis & Testing) >> St Generic Scan Tool >> Diagnosis And Testing >> Diagnostic Modes 01 - 0A >> Diagnostic Mode 08 - Request Control Of On-Board System, Test Or Component
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Diagnostic Mode 08 - Request Control Of On-Board System, Test Or Component

Diagnostic Mode 08 is used to control the operation of an on-board system, test or component. A Mode 8 service can be used to turn an on-board system ON or OFF, or to cycle an on-board system, test or component on or off for a specific period of time. The service can also be used to request system status or to report test results.

Test requirements 

Function test 

NOTE:

If the accelerator pedal is depressed during the test, the test will be aborted.

-- Connect the scan tool.

-- Start the engine and run at idle for at least 15 minutes.

-- Select "Mode 8: Tank Leak Test".

-- Select "Test-ID 01: Tank Leak Test".

-- Check the specified value of the tank leak test at idle.

-- The following will be displayed on the scan tool screen:

Tank Leak Test Specified Value
  • Test function active.
  • Test function is being initiated, please wait.
  • Test off.
  • Test aborted.
Test OK.

-- Switch the ignition off.

If the specified result is obtained:

System OK.

If the specified result is Not obtained:

-- Repeat the tank leak test, switch the ignition off and start the engine again and let run for 15 minutes at idle.

-- Switch the ignition off.

If the specified result is again Not obtained:

-- A leak may be present. Refer to EVAP SYSTEM, CHECKING FOR LEAKS .