5 Series E60 520d (N47) SAL
The most common causes of a fuel tank leak fault are:
Fuel filler cap fitted crooked or not correctly
Fuel filler cap not turned as far as it will go to the end stop (the end stop is
indicated by a clearly audible "click")
Retaining strap for fuel filler cap trapped between the filler cap itself and the
fuel filler neck
Also refer to Service Information SI 16 02 99 (501) with regard to the fault patterns
Proceed as follows if a tank leak fault is stored in the fault memory:
Clear the fault memory
Check whether the fuel filler cap is fitted correctly
Work through test module:
DMTL system test
For further details, please refer to Repair Instructions 16 00 102 (M54).
If a leak is detected in the fuel supply system on completion of the test module this leak will
be caused by the fuel filler cap not being closed correctly.
The costs in connection with the above causes are not incurred by any technical
defects in the system and no warranty claims for reimbursement will be accepted.
A fuel tank leak test must be carried out if the fuel supply system is found to be leaking.
Case 3. Tank leak search
The fuel tank leak test procedure is described in Repair Instructions 16 00 510.
With the "DMTL pump actuation" service function, the internal solenoid valve (14, Fig. 2) in
the DMTL closes the line to atmosphere and the DMTL pump is subsequently activated.
As a result, the fuel supply system is a closed system and pressure is built up.
The leak can now be found with the aid of a leak detector.
External pressure must not be applied to systems with DMTL because, in this
case, the DMTL valve is not closed and a leak will inevitably be detected.
During the above service function, the DMTL pump runs uninterrupted for
approx. 15 minutes . After this, the DME switches the DMTL pump off. If
necessary, the test module can be repeated after a short waiting period.
Probable leak points:
Fuel filler cap screwed on crooked or not up to the stop
(8, Fig. 2)
Fuel level sensor left or right leaking (replace sealing ring)
SI Diagnosis of fuel tank systems with fuel tank leak diagnosis module (DMTL) All U
BMW AG - TIS
Issue status (12/2007) Valid only until next DVD is issued
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