EGR Temperature Sensor: Testing and Inspection

Check With VAG 1551 Scan Tool In "Read Measuring Value Block" Function, Testing Closed Throttle Position.

- VAG 1551 Scan Tool connected with "Read Measuring Value Block" Function Selected Display Group 02.

Indicated On Display:

Read Measuring Value Block 2
1 2 3 4

- No leaks in vacuum lines and hose connections
- Vacuum lines not plugged or kinked
- Engine oil temperature min. 50°C (122°F)




- Disconnect EGR Vacuum Regulator Solenoid Valve (N18) -1-.
- Connect VAG 1390 vacuum pump to the disconnected hose.
- Operate vacuum pump.
- Performance at Closed Throttle Position must get noticeably worse.

If NO:
- Check lines and connections for obstructions and clean if necessary.
- If necessary, Replace EGR Valve.

If Idle Gets Worse:
- Read EGR temperature in display field 4. Temperature must rise steadily without interruption.
- If display reads 127.4°C, or if the temperature drops, there is an interruption.
- As soon as the temperature value reaches 200°C, disconnect vacuum pump.
- Press -> button.
- Press buttons -and -6- for "End Output" Function.
- Press -Q- button to confirm input.

If no fault is found:
- Replace EGR Temperature Sensor (G98).