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Checking holding pressure > < Checking function and voltage supply (engine codes CBTA, CBUA)

Golf Mk6

Checking fuel pressure
Checking fuel pressure
  WARNING
Fuel supply line is pressurised. Wear eye protection and protective clothing to avoid possible injury and skin contact. Before loosening hose connections, wrap a cloth around the connection. Then release pressure by carefully pulling hose off connection.
   
–  Pull off supply line (metal coupling) -arrow- and catch escaping fuel with a cloth. Separate push-on coupling → Chapter
  A20-10135
–  Connect pressure tester -VAS 6550- to fuel supply line with adapter -VAS 6550/1- and -VAS 6550/2-.
–  Make sure that drain tap is closed and cut-off taps are open.
–  Actuate fuel pump with final control diagnosis to build up fuel pressure.
–  Read fuel pressure on pressure gauge.
l  Specification: 4.0…7.0 bar.
If fuel pressure is OK, check holding pressure → Chapter.
If the specification is exceeded:
–  Check return line between fuel filter and fuel pump for kinks and blockages.
If no fault is found:
–  Pressure limit valve in fuel filter is defective. Renew fuel filter.
If the specification is not attained:
–  Check fuel pressure upstream of fuel filter; proceed as follows:
  N20-10628
–  Detach fuel supply line -arrow- from fuel filter → Chapter.
  N20-10629
–  Connect pressure tester -VAS 6550- between fuel filter and fuel supply line with adapter -VAS 6550/1- and -VAS 6550/2-.
–  Make sure that drain tap is closed and cut-off taps are open.
–  Actuate fuel pump with final control diagnosis to build up fuel pressure.
  N20-10630
–  Close shut-off valve -A- slowly. Pressure must rise to min. 7.0 bar. When 7.0 bar is reached, open shut-off tap again immediately.
If pressure has risen:
–  Fuel pump is OK. Pressure limiting valve in fuel filter is defective. Renew fuel filter.
If pressure does not rise:
–  Fuel pump defective, renew fuel delivery unit → Chapter.
  N20-10598

Checking holding pressure > < Checking function and voltage supply (engine codes CBTA, CBUA)