Fuel Delivery and Air Induction: Testing and Inspection

Intake System, Checking For Leaks (Unmetered Air)

Special tools and equipment







- VAS5051 with VAG5051/1
- Engine leak detection spray G 001 800 A1


NOTE:
- The negative pressure in the intake system sucks in the leak detection spray with the unmetered air. Leak detection spray decreases ignition quality and performance of the fuel mixture. This causes a reduction in engine speed and a sharp increase of CO content.
- It is absolutely necessary to follow the safety precautions listed on the can.


Test sequence
- Connect VAS5051 tester and select vehicle system "01 - Engine electronics". Engine must run at idle for this. Refer to "Scan Tool Testing/Scan Tool Connecting and Initial Checks/VAS 5051 Tester, Connecting and Selecting Functions" Testing and Inspection







Display on VAS5051:
- Select diagnostic function "08 - Read Measuring Value Block" in selection -1-







Display on VAS5051:
1 - Enter display group Max. input value = 255
- Select function "001" in button field -2- for "display group number 001" and press Q button to confirm input.







Display on VAS5051:
- Make note of engine speed in display field-1.
- Spray intake system parts with engine leak detection spray in a systematic manner.

If engine speed decreases:
- Check sprayed part of intake system for leaks, and eliminate the error.
- Press "08 - erase DTC memory" to end function <- button.
- Select "06 - End Output"
- Switch ignition off.