Checking fuel delivery rate of fuel system pressurisation pump G6 — VW

Checking fuel delivery rate of
fuel system pressurisation pump
G6
Special tools and workshop equipment required
Hand-held multimeter
V.A.G 1526E
Pressure gauge
VAS 6551
Hose adapter
VAS 6551/1
Hose adapter
VAS 6551/2
Torque wrench
V.A.G 1332
Vehicle diagnosis tester
Test sequence:
Delivery pressure of fuel pump (fuel low pressure) has been checked previously
Chapter
Fuel tank at least
3
/
4
full.
Connect charger or battery voltage above 12.5 volts
»Carry out the following work sequence«
WARNING
Always read rules for cleanliness and instructions for working on fuel system
Chapter
.
Always follow these rules for cleanliness and instructions before starting work and while working on the fuel system.
Wrap a clean cloth around the connection before opening the fuel system, then carefully loosen the connection to release the pressure.
Pull fuel supply line (black or black marking)
4
off fuel delivery unit. Separate connectors
Chapter
.
Collect escaping fuel with a cleaning cloth.
Connect connection
A
of
pressure tester
VAS 6551
with line
VAS 6551/1
to open end of fuel delivery unit.
From connection
B
, route
hose adapter
VAS 6551/2
into a ≥ 3 litre measuring container
3
and hold there.
Switch on
pressure tester
VAS 6551
by pressing
On/Off
button.
Open shut-off taps
“B”
+
“C”
of
pressure tester
VAS 6551
.
Switch ignition on.
Connect
vehicle diagnosis tester
and carry out guided function
“Fuel pump activation (checking fuel pump)”
.
Note
The fuel pump is now activated for 30 seconds.
Carefully open shut-off tap
B
completely.
Slowly close shut-off tap
B
while reading pressure displayed on
pressure tester
VAS 6551
. Set specification of 5 ± 0.2 bar by closing the tap carefully.
Drain measuring container.
Repeat function
“Fuel pump activation (checking fuel pump)”
.
The amount of fuel delivered by the
fuel pump
depends on the voltage at the fuel delivery unit.
Therefore, also connect
multimeter
V.A.G 1526
to outputs
1 and 5
of
test instrument/DSO adapter 5-pin
VAS 5565
.
Test prerequisites
At RT = room temperature or a fuel temperature of T = (20 +- 5) °C .
At a pressure of 5 ± 0.2 bar at flange output
During the checking process, there must be voltages of 11 to 15 volts at the fuel pump. Measured at the flange connector of the delivery unit.
Carry out guided function
“Fuel pump activation (checking fuel pump)”
.
Compare the amount of fuel delivered with the read value from the table.
*) Delivered amount of fuel in ml/30 s
**) Voltage at fuel delivery unit (V) with engine not running and pump running.
Example:
During the test, a voltage of 12.0 volts, for example, is measured at the fuel delivery unit.
The delivered amount of fuel is therefore 1100 ml/30 s.
If the required amount of delivered fuel is achieved, or if more is measured:
Fuel pump
ok.
If the amount of fuel to be delivered by the
fuel pump
is not achieved, the following faults have occurred:
Battery voltage below 12.5 V (connect charger)
Fuel delivery unit filter strainer soiled. Check filter strainer for soiling
Chapter
.
Voltages in the range from 11 to 15 volts were not reached during the testing process.
Check voltage supply of
fuel pump
Chapter
.
Check current consumption of
fuel pump
Chapter
.