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Volkswagen Workshop Service and Repair Manuals

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Checking fuel pressure (engine codes CAVA, CAVB, CAVC, CAVD) > < Checking function and voltage supply (engine codes CAVA, CAVB, CAVC, CAVD)

Golf Mk5

Checking function and voltage supply (engine codes CBTA, CBUA, BGP, BGQ)
Checking function and voltage supply (engine codes CBTA, CBUA, BGP, BGQ)
l  Fuel pump relay -J17- OK
l  Battery voltage at least 11.5 V
l  Fuse for fuel pump OK. Fuse assignment → Current flow diagrams, Electrical fault finding and Fitting locations
  Note
Function of fuel pump is checked using final control diagnosis.
   
–  Connect vehicle diagnosis tester as follows:
–  Push diagnosis cable connector onto diagnosis connection in driver footwell.
–  Switch on ignition.
–  Press buttons on display one after the other for Vehicle self-diagnosis, Engine electronics and Final control diagnosis.
–  Press right arrow button ► on display to initiate actuation of fuel pump.
The fuel pump must now start up.
–  Switch off ignition.
If fuel pump does not run:
–  Remove bench seat → General body repairs, interior; Rep. gr.72.
  N01-0590
–  Remove cover from fuel delivery unit.
  A20-1206
–  First check that the connector -arrow- is fitted securely by pulling the connector without pressing the catch. If connector was not inserted correctly, repeat functional check of fuel pump.
–  Now pull off connector.
–  Check the contacts on the connector and on the fuel delivery unit for damage.
  N20-10623
–  Connect test instrument adapter/DSO (5-pin) -VAS 5565- to connector and fuel delivery unit.
–  Connect multimeter -V.A.G 1526D- to cables -1- and -5- of test instrument adapter/DSO (5-pin) -VAS 5565-.
–  Initiate final control diagnosis again and measure voltage at fuel pump.
l  Specification: approx. 2 V less than battery voltage.
Voltage supply not OK:
–  Locate and eliminate open circuit referring to current flow diagram → Current flow diagrams, Electrical fault finding and Fitting locations.
Voltage supply OK:
  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.
  N20-10423
–  Pull fuel lines -1- and -2- off flange. Separate push-on couplings → Chapter.
  Note
On vehicles with auxiliary heater the connector and the fuel line of the metering pump -V54- must also be separated.
  N20-10624
–  Open locking ring using wrench -T10202-.
–  Check that electrical wires between flange and fuel pump are connected.
If no open circuit can be found:
–  Fuel pump defective, renew fuel delivery unit → Chapter.
  N20-10625

Checking fuel pressure (engine codes CAVA, CAVB, CAVC, CAVD) > < Checking function and voltage supply (engine codes CAVA, CAVB, CAVC, CAVD)