Fuel Delivery and Air Induction: Testing and Inspection

Intake Air System, Checking For Leaks (Unmetered Air)

Checking with engine leak detector spray G 001 800 A1

Special tools and equipment
- VAG 1551 Scan Tool or VAG 1552 with cable VAG 1551/3
- Engine leak detector spray G 001 800 A1

Test conditions
- Coolant temperature must be at least 85 degree C, See display group 04, display zone 3.

Test sequence

NOTE:
- The vacuum in the intake system will cause the leak detector spray to be drawn in with the unmetered air. The leak detector spray reduces the ignitability of the mixture. This leads to a drop in engine speed and to a change of Oxygen sensor reading.
- Always adhere to the safety precautions listed on the container.


- Connect VAG 1551 Scan Tool ((VAG 1552). Start engine and select "Address word" 01 of engine control module. When doing this engine must be running at idle speed.

Indicated on display

Rapid data transfer HELP
Select function XX

- Press keys 0 and 8 for function "Read Measuring Value Block" and confirm entry with Q key.

Indicated on display

Read Measuring Value Block HELP
Input display group number XXX

- Press keys 0, 0 and 1 for "Display group number 1" and confirm entry with Q key.

Indicated on display: (1 to 4 Display zones)

Read Measuring Value Block 1 ->
1 2 3 4

- Observe engine speed in display zone 1 and Oxygen sensor control in display zone 3.
- Systematically spray parts of intake system with engine leak detector spray.

If the engine speed drops or the Oxygen sensor control changes:
- Press -> key.
- Press keys 0 and 6 for "End data transfer" function and confirm input with Q key.
- Switch ignition off.
- Check sprayed areas of intake system for leaks and rectify if necessary.