Audi Workshop Service and Repair Manuals > A4 Mk2 > Power unit | 4-Cylinder engine (2-valve), Mechanics | Exhaust system | Exhaust gas recirculation system | Checking adaption of zero position for exhaust gas recirculation valve N18

Checking adaption of zero position for exhaust gas recirculation valve N18

Checking adaption of zero position for exhaust gas recirculation valve -N18-

Note

t	After renewing the engine control unit or the exhaust gas recirculation valve -N18-, the engine control unit and exhaust gas recirculation valve must be adapted to one another → Simos injection and ignition system (4-cyl.); Rep. Gr.24.

t	Check the adaption status and the zero position before performing repair measures.

Special tools and workshop equipment required

t	Vehicle diagnostic, testing and information system -VAS 5051 A- with diagnosis lead -VAS 5051/5A-

Test sequence

–	Connect up vehicle diagnostic, testing and information system -VAS 5051 A- with diagnosis lead -VAS 5051/5A- and select vehicle system “01 - Engine electronics” from list. Engine must be idling.

–	Under -1- select diagnostic function “04 - Basic setting”.

–	Enter “074” for “display group number 074” in zone -2- and confirm the entry by pressing the Q key.

1 -	Enter display group

–	Activate basic setting by touching button A.

–	Check display in zones -1- and -4-.

Display zone	Readout	Specification
1	Zero position: x.x V	0.3 ... 1.2 V → Note
4	Adaption status: ADP. runs ADP. O.K. ERROR	ADP. O.K. → Note

¹⁾	If the specification is not attained, check the exhaust gas recirculation valve for dirt and foreign objects; renew valve if necessary.

²⁾	If the specification is not attained: check the exhaust gas recirculation valve using “Guided Fault Finding” → Vehicle diagnosis, testing and information system VAS 5051.

Note

The abbreviation “ADP” in display zone 4 stands for “Adaption”.

–	Terminate function “04 - Basic setting” by pressing the ← key.

–	Press “06 - End output”.

–	Switch off ignition.

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