Testing idling stabilisation valve -N71: Audi 2.0 (ABK, ADW)

ADW
Special tools, testers and auxiliary equipment required

Hand-held multimeter V.A.G 1526 or V.A.G 1526 A
Voltage tester V.A.G 1527 B
Fault reader V.A.G 1551 (or vehicle system tester V.A.G 1552) with wire V.A.G 1551/1
Adapter set V.A.G 1594 A
Test box V.A.G 1598/18

Testing internal resistance

Switch off ignition.
Pull connector -arrow- off idling stabilisation valve.

Set hand held multimeter V.A.G 1526 to resistance measuring range and connect to valve contacts using test leads from V.A.G 1594 A.
Specification: 2 ... 10 ω

Note:

Resistance is in the lower tolerance range at ambient temperature and in the upper tolerance range when the engine is warm.

If the specification is not obtained:

Renew idling stabilisation valve.

Mechanical checking

Remove idling stabilisation valve
Inspect the piston slide for signs of rubbing (visual inspection).

Note:

Never use a screwdriver or similar tool to move the piston slide when checking for freedom of movement.

Attach connector to removed idle stabilisation valve

Switch the ignition on.
Start final control diagnosis and actuate the idling speed stabilisation -N71 an => Page
01-36
.
Test whether piston slide moves properly from stop to stop.

If scoring is found which impairs freedom of movement or if piston slide does not move freely (sticking, sluggish or not full range of travel):

Renew idling stabilisation valve.

If idling stabilisation valve does not react in final control diagnosis:

Test the voltage supply or the actuation.

Testing power supply

Push back protective cap at connector
Set hand-held multimeter V.A.G 1526 to voltage measuring range (20 V direct current) and connect to contact 1 and to engine earth using test leads from V.A.G 1594 A.
Switch the ignition on.
Specification: approx. battery voltage

If the specification is not obtained:

Use current flow diagram to eliminate open circuit in wiring/short circuit.

Testing actuation of the idling speed stabilisation valve

Pull connector -arrow- off idling stabilisation valve.
Connect voltage tester V.A.G 1527 B between contact 1 (positive) and 2 (signal) of the connector.

Connect fault reader V.A.G 1551 and select engine electronics control unit => Page
01-2
.
Start final control diagnosis and actuate the idling speed stabilisation -N71 an => Page
01-36
.
The LED should flash.

If the LED lamp does not flash or if it lights up continuously:

With the ignition switched off, connect test box V.A.G 1598/18 to connector for engine control unit => Page
24-16
.

Test for open circuit and short to earth/positive or earth in the following wiring connections:

Connector / for -N71 / Contact · Test box V.A.G 1598/18 / / Socket
2 · 30

Rectify any open/short circuit as necessary.
If actuation and wiring are OK, but idling stabilisation valve does not react, valve is seized up. Renew idling stabilisation valve.