With VAG 1551

CHECKING EGR VALVE AND EGR TEMPERATURE SENSOR

NOTE: Checks are made using the VAG 1551 Scan Tool (ST) in "Read Measuring Value Block" function (08), with the engine running at idle (Closed Throttle Position).

REQUIREMENTS
^ Vacuum lines and hose connections free of leaks.
^ Vacuum lines not blocked or kinked.
^ Engine oil temperature at least 50°C (122°F).

PROCEDURE
- Connect VAG 1551 Scan Tool in "Rapid data transfer" operating mode.
- Input address word 01 for "Engine Electronics." Carry out selection with engine idling.

^ Indicated on display:

Rapid Data Transfer HELP
Select function XX

- Input 08 to select "Read Measuring Value Block" function, and press -Q- button to confirm input.

^ Indicated on display:

Read measuring value block HELP
Input display group number XX

- Input display group number 02 and press -Q- button to confirm input.

^ Indicated on display: (1 - 4 Display fields)

Read measuring value block 2
1 2 3 4

NOTE: If the display remains blank, refer to VAG 1551 Scan Tool operating instructions.

- Disconnect vacuum hose from EGR Valve.



- Connect VAG 1390 hand vacuum pump to EGR Valve using auxiliary hose.
- Operate pump to apply vacuum.

NOTE: Idle characteristics must deteriorate noticeably.

- If the idle characteristics DO NOT deteriorate:

- Check lines and connections and clean any that are blocked. If necessary replace EGR Valve.

- If the idle characteristics DO deteriorate:

- Read EGR temperature value in display field 4. The temperature figure must increase uniformly without interruption.
- As soon as the value in display field 4 reaches 200°C, disconnect hand vacuum pump.
- Press --> button.
- Input 06 to select "End Output" function and press -Q- button to confirm input.

- If the EGR Temperature value does NOT change:

- Check activation of EGR Vacuum Regulator Solenoid Valve (N18).

- If the EGR Valve clicks during the electrical check:

- Replace EGR Temperature Sensor (G98).
- Check Diagnostic Trouble Code (DTC) Memory.