Leak Test On Fuel Tank

WARNING: This page is about a different variant/trim than selected.

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.

→ Contain leaked media using non-flammable absorbent material and put it in a container designed for this purpose for disposal in accordance with local requirements.

→ Secure collection containers/vessels to prevent them from tipping over.

Information

Perform the leak test, only for vehicles with leakage diagnosis module.

Attach warning sign -1- in a clearly visible position on the vehicle or position it in the immediate working area.

Courtesy of PORSCHE CARS NORTH AMERICA, INC.

Example of warning sign when working on the fuel system

Information
- Perform the leak test using the Tester routine without battery charger!
Perform fuel tank leak test using the PIWIS Tester in 2 steps.
1. Step 1: Verify leak.
2. Step 2: Verify leak-tightness.
Carry out the instructions shown on the Tester for Step 1 (Verify leak) .
Connect the PIWIS Tester in the vehicle and carry out preparatory steps:
- Remove fuel tank cap.
- Select DME control unit.
- Read out the fault memory. There must be no fault memory entries! If there are fault memory entries → Erase DME fault memory .
- Select the Maintenance/repairs menu.
- Select he sub-menu item Tank leak test .
- Observe information and preconditions! => Press F8 to start.
At the end of Step 1, read out the fault memory. Since the tank filler neck is open, you can expect one of the following fault entries:
- P0456
- P0442
- P0455
If there are no fault entries, the diagnostic line is blocked/closed.

=> Clean or replace the line!

If there are fault entries => Clear the fault memory!
Continue the test with Step 2 (Verify leak-tightness) and carry out the instructions shown on the Tester.
Connect the PIWIS Tester in the vehicle and carry out preparatory steps:
- Close the fuel tank cap again.
- Select DME control unit.
- Select the Maintenance/repairs menu.
- Select sub-menu item Tank leak short test .
- Observe information and preconditions! => Press F8 to start.
At the end of Step 2, read out the fault memory.

=> No faults = System OK!

If there are fault entries, correct faults as instructed (guided fault finding).