16 00 100 Checking Fuel Tank and Tank Ventilation System For Leaks

16 00 100 Checking Fuel Tank And Tank Venting System For Leaks (not US Version With DMTL)

Special tools required:







Note:
The following procedure is only applicable to vehicles without the tank leak diagnosis module.
Check tank venting system if a leak is suspected.







Necessary preliminary tasks:
- Remove rear right wheel arch trim

Comply with the following conditions in order to obtain plausible test results:
- Content of fuel tank:
1. Maximum 90 %
2. Minimum 13 % (reserve telltale must not light up).
- Park the car in the workshop at least 2 hours before the test so that the fuel temperature is approximately that of the workshop temperature (ideal fuel temperature approx. 10 ... 20 °C).
- Never refuel the vehicle directly prior to the leak test due to the strong emission of gas by the fresh fuel.







Using special tool 16 1 070, seal opening (1) on carbon canister.







Remove fuel filler cap and connect special tool 16 1 174 to fuel filler neck.
Clamp special tool 16 1 174 on fuel filler neck with adjusting wheel (1).







IMPORTANT:
Set pressure regulator on special tool 16 1 171 fully in " - " direction.







Connect special tool 16 1 171 using compressed air line (1) to garage compressed air system (8 ... 10 bar).
Connect pressure sensor (2) from Diagnosis and Information System with a measuring range of 0...3.5 bar.

IMPORTANT:
Do not yet connect fast-release coupling (3) of special tool 16 1 171.







Select "Measurement" function on Diagnosis and Information System (DIS).
Using pressure regulator on special tool 16 1 171, increase pressure by 0.050 bar.
Connect special tool 16 1 174 to fast-release coupling of special tool 16 1 171.
Using pressure regulator on special tool 16 1 171, reset gauge pressure in fuel tank to 0.050 bar.







IMPORTANT:
Do not under any circumstances increase pressure by more than 0.05 bar as this would result in damage to the fuel tank and venting system.

Using special tool 13 3 010, disconnect delivery line from special tool 16 1 171 to fuel filler neck.
Allow a rest period of approx. 20 secs.
Read off and note down starting pressure value.
Wait approx. 60 secs.
Read off final pressure value and compare with starting pressure value.

Measurement evaluation: