Exhaust Gas Recirculation (EGR) valve and EGR temperature sensor -G98-, checking

WARNING: This page does not describe the selected car, but rather 25 other vehicles, including the 2002 Volkswagen Cabrio, 2001 Volkswagen Cabrio, 2000 Volkswagen Cabrio, 1999 Volkswagen Jetta, and 1999 Volkswagen Golf. However, it is still accessible from the selected car via links, so may be relevant.

Check with VAG1551 Scan Tool (ST) in "Read Measuring Value Block" function 08, testing closed throttle position.

VAG1551 Scan Tool connected with "Read Measuring Value Block" function selected (display group 002). See appropriate On Board Diagnostic (OBD) article.

Indicated on display

Fig 1: Indicating On Display Read Measuring Value Block 2

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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- (item -1-).
Connect VAG1390 vacuum pump to disconnected hose.

Fig 2: Connecting VAG1390 Vacuum Pump To Disconnected Hose
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Operate vacuum pump.

Performance at Closed Throttle Position (CTP) 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 -0- and -6- to select "End Output" function 06.
Press -Q- button to confirm input.

If temperature does not change:

Perform electrical testing in appropriate On Board Diagnostic (OBD) .

If no malfunction is found:

Replace EGR temperature sensor -G98-. See EXHAUST GAS RECIRCULATION (EGR) VALVE AND EGR TEMPERATURE SENSOR -G98-, CHECKING .