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Home >> Volkswagen >> 2004 >> Passat Wagon 4Motion (3B6) W8-4.0L (BDP) >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Testing and Inspection >> Scan Tool Testing and Procedures >> Diagnostic Mode 8: Tank Leak Test

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.
- Using 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.
- Coolant temperature must be 80 to 110 degrees C, Diagnostic mode 1: Check measuring values; PID 5, Coolant temperature. Diagnostic Mode 1: Check Measuring Values
- Intake air temperature must not be above the maximum of 60 degrees C, Diagnostic mode 1: Check measuring values; PID 15, Intake air temperature. Diagnostic Mode 1: Check Measuring 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.

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 at idle for at least 15 minutes.


- End diagnostic and switch ignition off.

If a leak is detected:
- 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
- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data.
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes
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