If Reading Matches Specification; If No Fault Is Found; If Specification Is Not Obtained - Volkswagen CC 2012 Workshop Manual

– Ensure that drain tap -C- on pressure tester -1- is closed.
– Shut-off valves -A- and -B- on pressure tester -1- are open.
– Repeat final control diagnosis to build up fuel pressure
⇒ page 78 .

If reading matches specification:

– Check fuel lines for possible restrictions (kinks) or blockages.
– Check fuel line for leaks and damage.

If specification is not obtained

– Remove fuel delivery unit and check for contamination
⇒ "2.2 Removing and installing fuel delivery unit, fuel gauge
sender", page 43 .
– Check that all hoses are connected.
– Check fuel lines for possible restrictions (kinks) or blockages.
– Check fuel lines for leaks and damage.

If no fault is found:

– Renew flange for fuel delivery unit
⇒ "2.2 Removing and installing fuel delivery unit, fuel gauge
sender", page 43 .
Note
Pressure limiting valve and fuel filter are integrated in flange of
fuel delivery unit and cannot be renewed individually.
– Repeat fuel pressure test on fuel delivery unit
If specification is not obtained
– Fuel pump is defective; renew fuel delivery unit
⇒ "2.2 Removing and installing fuel delivery unit, fuel gauge
sender", page 43 .
8.1.3 Checking fuel pressure during vehicle
operation, engine codes CCZB, CDAA,
CDAB
Note
If a complaint is made about the driving behaviour, the reason
♦
may be that the fuel pressure is too low. Faults in the high-
pressure section may also be caused by inadequate fuel
pressure in the low-pressure section. This check determines
the fuel pressure in the high-pressure and low-pressure sec‐
tions during a road test. The fuel pressure in the high-pressure
section is read from the engine control unit. The low fuel pres‐
sure is measured using pressure tester - VAS 6550- and
⇒ Vehicle diagnostic tester.
This test can be part of "Guided Fault Finding" if an entry has
♦
been made in the event memory.
With the ⇒ Vehicle diagnostic tester this test can also be star‐
♦
ted via "Function/component selection".
Special tools and workshop equipment required
CC 2012 ➤ , Passat 2011 ➤ , Passat Variant 2011 ➤
Fuel supply system, petrol engines - Edition 05.2019
⇒ page 78 .
81
8. Fuel pump