Audi Workshop Service and Repair Manuals

Checking camshaft control valves (solenoid valves)

Special tools and workshop equipment required

t	Hand-held multimeter -V.A.G 1526 B- or -V.A.G 1526 A-

t	Voltage tester -V.A.G 1527 B-

t	Auxiliary measuring set -V.A.G 1594 C- or -V.A.G 1594 A-

t	Test box -V.A.G 1598/22- (vehicles with throttle cable)

t	Test box -V.A.G 1598/31- (vehicles with electronic throttle)

t	Vehicle diagnosis, testing and information system -VAS 5051- with diagnosis lead -VAS 5051/1-

Test conditions l  Vehicle diagnostic, testing and information system -VAS 5051- with diagnosis lead -VAS 5051/1- is connected; vehicle self-diagnosis and vehicle system “01 - Engine electronics” is selected. When doing this, the ignition must be switched on. l  Vehicles with automatic gearbox: selector lever in position “P” or “N”

Test sequence Display on -VAS 5051- –  From the menu -1- select the diagnostic function “03 - Final control diagnosis”. –  Keep touching → key until camshaft control valves are activated. l  Camshaft control valves should click. –  Press the ← key to exit from function “03 - Final control diagnosis”. –  Switch off ignition. If one of the valves is not activated (does not click):

Checking internal resistance –  Take off engine cover panel -arrows-.

–  Unplug electrical connector at relevant solenoid valve. –  Connect multimeter (resistance measuring range) to valve. l  Specification: 10 ... 18 Ω. If specification is not obtained: –  Renew solenoid valve.

Checking voltage supply l  Fuse for camshaft control valves OK → Current flow diagrams, Electrical fault finding and Fitting locations. l  Fuel pump relay -J17- OK.   Note The camshaft control valves are supplied with power via the fuel pump relay. –  Unplug electrical connector at relevant solenoid valve. –  Connect voltage tester -V.A.G 1527 B- between contact -1- and earth. –  Operate the starter briefly. l  The LED should light up. If LED does not light up: –  Check for open circuit in wiring from contact 1 of connector via fuse to fuel pump relay → Current flow diagrams, Electrical fault finding and Fitting locations. –  Eliminate open circuit in wiring if necessary. If the LED lights up:

Checking activation –  Connect voltage tester -V.A.G 1527 B- to contacts -1- (plus) and -2- of the connector. –  Repeat function “03 - Final control diagnosis”. –  Keep touching → key until camshaft control valves are activated. l  The LED should flash. –  Press the ← key to exit from function “03 - Final control diagnosis”. –  Switch off ignition. If the LED does not flash or lights up continuously: –  Connect test box -V.A.G 1598/22- or -V.A.G 1598/31- to wiring harness for engine control unit, but do not connect the engine control unit itself → Rep. Gr.24.

–  Check for open circuit and short to earth/positive in the following wiring from inlet camshaft control valve 1 -N205- or inlet camshaft control valve 2 -N208-: Vehicles with throttle cable:

Connector Contact	Test box -V.A.G 1598/22- Socket
-2-	55

Vehicles with electronic throttle:

Connector Contact	Test box -V.A.G 1598/31- Socket
-2-	115

All models: –  Repair wiring connection if necessary. If wiring is OK: –  Fit a new engine control unit → Rep. Gr.24. If no fault is found: –  Renew mechanical camshaft adjuster → Chapter „Removing and installing camshafts and camshaft adjuster“.