Test Sequence:
-- Remove the bench seat. Refer to REAR SEATS .
Vehicles with Engine Codes CBTA, CBUA, CCCA:
-- Remove the cover -1- from the fuel delivery unit. The arrow -2- points in the direction of travel.
Continuation for All Other Vehicles:
-- Remove the cover -1- with the Fuel Pump Control Module -J538- -2- from the fuel delivery unit.
Continuation for All Vehicles:
-- Pull on the connector -1- without pressing the release to make sure the connection is secure. If the connector was not connected correctly, it could cause a malfunction.
-- Remove the connector -1-.
-- Check the contacts on the connector and on the fuel delivery unit for damage.
-- Connect the :VAS5565 to the connector and to the fuel delivery unit.
-- Connect the :VAG1348/3A to the :VAS5565 and the battery positive clamp in the engine compartment.
This step allows the fuel pump to run when the engine is not running.
-- The fuel pump delivery rate is dependent on the battery voltage. Also connect the analog/digital multimeter to the wires -1 and 5- in the :VAS5565 .
-- Remove the fuel line -arrow- and wipe up the leaking fuel with a cleaning cloth. Disconnect the connector couplings. Refer to CONNECTOR COUPLINGS, DISCONNECTING .
The fuel system is under pressure.
Risk of injury from fuel spraying out.
- Wear protective eyewear.
- Wear safety gloves.
- Reduce the pressure: place clean cloths around the connection point and carefully open the connection point.
-- Connect the :VAS6550 with the :VAS6550/2 to the flange.
-- Connect the :VAS6550/2 to the connection -A- on the :VAS6550 .
-- Connect the :VAS6550/4 to the connection -B- on the :VAS6550 .
-- Hold the open end of the :VAS6550/4 hose in a measuring container.
-- Make sure that the drain valve -C- on the :VAS6550 -1- is closed.
-- The shut-off valves -A and B- on the :VAS6550 -1- are opened.
-- Push the :VAG1348/3A .
The Transfer Fuel Pump -G6- is activated!
-- Adjust the pressure to 4.0 bar (58.01 psi) with the adjustment wheel on the :VAS6550/4 -arrow-.
-- From this point on do not move the adjustment wheel.
-- Empty the measuring container.
-- Press the remote control for 60 seconds while measuring the fuel pump voltage.
-- Compare the delivered quantity of fuel with the specified value in the table.
| Axis Designation | Unit |
|---|---|
| Minimum delivery rate | cm3 |
| Fuel pump voltage when the engine is idling and the pump is running | Volt |
Example:
During test, a voltage of 10.5 Volts is measured. This results in a minimum delivery quantity of approximately 1200 cm3 /60 s.
If the Specified Value Is Not Obtained:
-- Remove the fuel delivery unit and check the filter screen for contamination. Refer to FUEL DELIVERY UNIT/FUEL LEVEL SENSOR, REMOVING AND INSTALLING .
-- Check the fuel lines for leaks and damage.
-- Check whether the hose connections to the fuel delivery unit are connected.
If No Malfunction Was Detected:
-- Check the current draw of the fuel pump. Refer to CURRENT DRAW, CHECKING .
If no faults were found while checking the current draw:
-- Replace the fuel delivery unit flange. Refer to FUEL DELIVERY UNIT/FUEL LEVEL SENSOR, REMOVING AND INSTALLING .
The pressure relief valve and the fuel filter are integrated in the fuel delivery unit flange and cannot be replaced separately.
-- Repeat the fuel delivery rate test at the fuel delivery unit. Refer to FUEL PRESSURE, CHECKING .
If the Specified Value Is Not Obtained:
-- Replace the fuel delivery unit. Refer to FUEL DELIVERY UNIT/FUEL LEVEL SENSOR, REMOVING AND INSTALLING .
If the fuel delivery rate was reach, even though a fault in the fuel supply is still suspected (for example, intermittent loss of fuel supply):
-- Check the current draw of the fuel pump. Refer to CURRENT DRAW, CHECKING .