Component Tests and General Diagnostics

Special tools, testers and auxiliary items
- US 8012 Hand vacuum pump
- VAG 1551 Scan Tool or VAG 1552 Scan Tool with VAG 1551/3 adaptor cable

Checking conditions:
- Vacuum lines and hose connections leak tight.
- Vacuum lines not blocked/kinked.
- Engine oil temperature 50 °C minimum.

Test sequence:
Connect VAG 1551 Scan Tool (VAG 1552) and select "address word 01" engine electronics with engine idling.

Display will appear as shown:

Rapid data transfer HELP
Select function XX

Press 0 and 8 buttons to select Function 08:
- "Read measuring value block."
- Press Q button to confirm input.

Display will appear as shown:

Read measuring value block HELP
Input display group number XX

Press 0 and 1 buttons to select "display group number."
- Press Q button to confirm input.

Display will appear as shown: (1 to 4 = display zones).

Read measuring value block 1 --->
1 2 3 4

Only continue with check when engine coolant temperature is above 50°C (display zone 2.
- Press C button
- Press 0 and 2 buttons to select "display group number."
- Press Q button to confirm input.

Display will appear as shown: (1 to 4 = display zones).

Read measuring value block 2 --->
1 2 3 4

Read off figure shown in display zone 4.
- Specification: EGRn. active (EGR system not active).
- Increase engine speed
- Read off figure displayed in display zone 4.
- specification: EGR active (EGR system active).
- Disconnect vacuum hose from EGR valve.




Connect US 8012 hand vacuum pump to valve arrow-> using piece of hose.
- Operate hand vacuum pump.
- idle quality must noticeably deteriorate.

IF NO
Press -> button
- Press 0 and 6 buttons to select Function 06 "End output."
- Press 0 button to confirm input.
- Switch OFF ignition.
- Check pipes and connections for blockage, clean if necessary, replace EGR valve if necessary.
- Check EVAP canister purge regulator valve activation.
- Check DTC memory for any remaining DTCS.