16 00 510 Conducting Leak Test On Fuel Tank and Tank Ventilation System
The following procedure is only applicable to vehicles with the tank leak diagnosis module (DM-TL).
Select "Tank leak diagnosis module (DM-TL)" on Diagnosis and Information System (DIS).
- The leak diagnosis pump pressurizes the fuel tank and tank venting system for 30 secs.
- If pressure is required for more than 30 secs., reactivate the "Activate" button after 30 secs. in each case.
For vehicles without tank leak diagnosis module:
Pressurize fuel tank and tank venting system See 16 00 100 CHECKING FUEL TANK AND TANK VENTILATION SYSTEM FOR LEAKS
When leak-testing with a leak detector: follow manufacturer's operating instructions.
On vehicles with tank leak diagnosis modules (DM-TL), do not work with external pressurization as the tank venting system will leak under this condition.
On account of emerging fuel vapors, carry out all operations in well ventilated rooms. Or use a suitable extractor system.
Observe country-specific accident prevention and occupational safety regulations.
The leak test can be carried out with a leak detector.
Possible causes may be:
- Fuel tank cap leaking (check fuel cap pressure relief valve) See 16 11 130 CHECKING TANK CAP PRESSURE RELIEF VALVE
- Tank venting lines leaking (fuel tank carbon canister-tank venting valve)
- Tank venting valve leaking (engine compartment)
- Fuel level sensor flange on tank leaking