Diagnostic Mode 8: Tank Leak Test

Diagnostic mode 8: Tank leak test

Function
This diagnostic mode checks the fuel system for leaks.

NOTE:
- The Evaporative Emission (EVAP) Canister Purge Regulator Valve -N80- and Leak detection pump (LDP) -V144- seal the tank system.
- Pressure of (max. 70 mbar) can be applied to the fuel system via the test connection (in engine compartment, right) and via engine leak detection spray (e.g.: G 001 800 A1) leaks can be detected.

Test requirements
- There must not be any DTCs stored in DTC memory, Diagnostic mode 3: Check DTC memory. Diagnostic Mode 3: Check DTC Memory
- Coolant temperature must be 80 to 110 degrees C, Diagnostic mode 1: Check measuring values; PID 5, Coolant temperature. Diagnostic Mode 1: Check Measured Values
- Intake air temperature must not be above the maximum of 60 degree C, Diagnostic mode 1: Check measuring values; PID 15, Intake air temperature. Diagnostic Mode 1: Check Measured Values

Function test
- Connect diagnostic tester. Diagnostic Tester, Connecting
- Start engine and let run at idle for at least 15 minutes.
- Under address word 33, select "Diagnostic mode 8: Tank leak test".
- Select measuring value "Test-ID 01: Tank leak test".
- Check specified value of tank leak test at idle.

Test-ID 01: Tank leak test Specified value:
- Test function is being Test function active
initiated, please wait
- Test function aborted
- Test function active
- Test function off


NOTE:
- During tank leak test, Engine Control Module (ECM) limits "test function active" to approx. 12 minutes.
- If the accelerator pedal is depressed during the test, the test will be aborted.
- To repeat the tank leak test, switch ignition off and start engine again and let run at idle for at least 15 minutes.

If specified value is obtained:
- End diagnosis and switch ignition off.

If specified value is not obtained:
- EVAP canister system, checking for proper seal. Testing and Inspection
- Check Evaporative Emission (EVAP) Canister Purge Regulator Valve -N80-. Testing and Inspection
- Leak detection pump (LDP) -V144-, checking. Testing and Inspection