Volkswagen Workshop Service and Repair Manuals

Special tools, testers, measuring instruments and auxiliary items required

• ◆ Fault reader V.A.G 1551 or vehicle system tester V.A.G 1552 with cable V.A.G 1551/3
• ◆ Engine leak detector spray G 001 800 A1

Test sequence

Notes:

• ◆ 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 Lambda probe reading.
• ◆ The safety precautions listed on the container must be adhered to.

• ‒ Connect fault reader V.A.G 1551 (V.A.G 1552). Start engine and select "Address word" 01 of engine control unit. When doing this the engine must be running at idling speed.
  (Connecting fault reader and selecting engine control unit .)

• ‒ Press keys 0 and 8 for the function "Read measured value block" and confirm entry with Q key.

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

• ‒ Note engine speed in display zone 1.
• ‒ Note Lambda probe voltage in display zone 3 and the area it fluctuates in.
• ‒ Systematically spray parts of the intake system with engine leak detector spray.

If the engine speed drops or the Lambda probe voltage changes:

• ‒ Press ⇒ key.
• ‒ Press keys 0 and 6 for the function "End output" and confirm entry with the Q key.
• ‒ Switch off ignition
• ‒ Check sprayed areas of intake system for leaks and rectify if necessary.

Engine speed or Lambda probe voltage does not change:

• ‒ Press ⇒ key.
• ‒ Press keys 0 and 6 for the function "End output" and confirm entry with the Q key.