Fuel Pump: Testing and Inspection
WM 206601 Checking delivery rate of electric fuel pump - Turbo
Tools
Technical values
Preliminary work
1. Place protective covers on the vehicle to avoid damaging the vehicle.
Information
- The battery voltage must not fall below 12.5 volts during the fuel delivery rate check.
2. Check the battery charge state using a voltmeter or the PIWIS Tester 9718.
2.1. Connect a battery charger and set it to 12.5 volts.
3. Remove underbody covers.
3.1. Remove rear cover.
-> 519419 Removing and installing cover for rear underbody 519419 Removing and Installing Cover for Rear Underbody.
3.2. Remove centre part of middle cover.
-> 519319 Removing and installing cover for centre underbody 519319 Removing and Installing Cover for Centre Underbody.
Checking delivery rate of electric fuel pump
Information
- The battery voltage must not fall below 12.5 volts during the fuel delivery rate check.
1. Have special tool measurement adapter 9705 , a fuel-resistant container, a measuring cup and a stopwatch to hand for measuring the amount of fuel delivered.
Measurement adapter 9705
2. Attach or mount a warning sign in a clearly visible position on the vehicle.
Example of warning sign for naked flames
3. PIWIS Tester 9718 must be connected to the adapter line at the input socket in the vehicle and ignition must be switched on.
3.1. Switch off all loads, such as radio, air conditioning, etc. Switch on the Tester and select the relevant vehicle.
4. Select DME, Maintenance/repair and press F12 to continue.
5. Select Drain tank and press F12 to continue.
6. The following message is displayed.
Drain tank message
7. Have special tool measurement adapter 9705. a fuel-resistant container, a measuring cup and a stopwatch to hand for measuring the amount of fuel delivered.
8. Open the retaining clip -1- for the fuel lines on the underbody. To do this, unclip the locking lugs -arrow-.
Opening retaining clip on fuel lines
Warning
Highly inflammable or explosive materials
- Danger of fire or explosion
-> Avoid contact with hot parts or sources of ignition.
-> Use suction to remove ignitable vapours.
-> Attach warning sign in a clearly visible position.
9. Disconnect quick connector on the fuel supply line -1- by pressing in the locking lug and pulling off the connector. Soak up emerging residual fuel with a cloth
Quick connector on fuel pressure line
10. Connect the measurement adapter 9705 special tool to the fuel line using the rapid-action coupling. Make sure that the coupling is fitted correctly and securely (it must lock with an audible click).
10.1. Pull on the lines to check that they are secure.
Connecting the measurement adapter
11. Place the drainage hose after the pressure regulator into a petrol-resistant container. Make sure that the container does not tip over.
Example of tank
12. Have a stopwatch ready for the following measurement.
13. Start the Drain tank routine by pressing F8 Start and start the stopwatch at the same time.
Measuring time: 60 seconds!
13.1. Collect emerging fuel in a container you have to hand.
14. Press F8=Stop after 60 seconds to deactivate the routine.
15. Pour the collected fuel into a measuring cup and compare the quantity with the value specified below.
=> Volume: 5 l/min+/-0.25 l/min
16. Remove special tool measurement adapter 9705 and attach the rapid-action coupling to fuel supply line.
16.1. Collect escaping fuel. Check that the plug-in coupling is fitted correctly (it must lock with an audible click) by pulling the line apart.
17. Switch off ignition, switch off the PIWIS Tester and disconnect adapter line to the vehicle.
Subsequent work
1. Install underbody covers.
-> 519319 Removing and installing cover for centre underbody 519319 Removing and Installing Cover for Centre Underbody
-> 519419 Removing and installing cover for rear underbody 519419 Removing and Installing Cover for Rear Underbody
2. Disconnect the charger.
3. Remove protective covers from the vehicle.
4. Remove warning sign.