16 00 510 Conducting leak test on fuel tank and tank ventilation system

WARNING: This page does not describe the selected car, but rather 16 other vehicles, including the 2006 BMW 330Ci, 2005 BMW 330xi, 2005 BMW 330i, 2005 BMW 330Ci, and 2004 BMW 330xi. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: The following procedure is only applicable to vehicles with the tank leak diagnosis module (DMTL).

CAUTION: On vehicles with tank leak diagnosis modules (DMTL), 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 work in well ventilated rooms. Or use a suitable extractor system.
Observe country-specific accident prevention and occupational safety regulations.

In the Diagnosis and Information System (DIS), go to the "Function and component selection" page.

By selecting:

Service functions
Drive
Digital Motor Electronics
Activation DMTL pump

adopt test module in test schedule.

Switch to the test schedule and implement the "Activation DMTL pump" test module.

Tank leak diagnosis pump pressurizes fuel tank and tank venting system.

Carry out leak test.

Terminate test module after completing leak test.

NOTE: Tank leak diagnosis pump is automatically shut down after approx. 15 minutes due to risk of overheating. Allow pump to cool down for at least 15 minutes. Then continue procedure.

The leak test can be carried out with a leak detector. Follow manufacturer's operating instructions in doing so.

Possible causes of leaks are:

Tank cap leaking (check tank cap pressure relief valve). See 16 11 130 Checking filler cap pressure relief valve
Tank venting lines leaking (fuel tank - carbon canister - tank venting valve).
Tank ventilation valve leaky (engine compartment)
Fuel level sensor flange on tank leaking

Fig 1: Identifying Leak Detector

Courtesy of BMW OF NORTH AMERICA, INC.