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Checking fuel pressure when the engine is running (engine codes CCZA, CCZB, CDAA, CDAB) > < Checking function and voltage supply

Golf Mk5

Checking fuel pressure
Checking fuel pressure
  Note
The fuel pressure is checked by way of the final control diagnosis
  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.
  Note
Press in securing ring to release fuel line.
  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
–  Pull fuel supply line -arrow- off fuel filter.
  N20-10629
–  Connect pressure tester -VAS 6550- between fuel filter and fuel supply line with adapter -VAS 6550/1- and -VAS 6550/2-.
  N20-10630
–  Make sure that drain tap is closed and cut-off taps are open.
–  Switch ignition on and activate the fuel pump with the final control diagnosis function.
–  While the fuel pump is operating, close the shut-off tap -A-. 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 fuel pressure when the engine is running (engine codes CCZA, CCZB, CDAA, CDAB) > < Checking function and voltage supply