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 (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.

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 measured values; PID 5, Coolant temperature. Diagnostic Mode 1: Check Measured Values
- Intake air temperature must not be above the maximum of 60 degrees C. Diagnostic mode 1: Check measured 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 15 minutes at idle.
- Under address word 33, select "Diagnostic mode 8: Tank leak test".
- Measuring value "Test-ID 01: select Tank leak test".
- Check specified value of tank leak test at idle.

Evaluation test-ID 01: Tank leak test

Test function: Specified value:
- is being initiated, please wait Test function active
- aborted
- active
- 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 15 minutes at idle.
- End diagnosis and switch ignition off.

If a leak is detected:
- EVAP canister system, checking for proper seal. Evaporative Emission (EVAP) Canister System, Checking For Proper Seal
- Check Evaporative Emission (EVAP) canister purge regulator valve -N80-. Testing and Inspection
- Check Leak Detection Pump (LDP) -V144-. Testing and Inspection
- Erase DTC memory of Engine Control Module (ECM). Diagnostic mode 4: Reset/erase diagnostic data. Diagnostic Mode 4: Reset/Erase Diagnostic Data
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes