Check idling stabilisation valve -N71 — AUDI

Special tools,
testers and auxiliary items required

V.A.G 1526 A
V.A.G 1527 B
V.A.G 1594 A
V.A.G 1598 A
V.A.G 1598/12
VAS 5051 with VAS 5051/1 and VAS 5051/2

or

V.A.G 1551 with V.A.G 1551/1

Installation position => Installation position overview - Page
24-6

Note:

Checking operation:

▸08.92=> basic setting, display group 000, display zone 4, Page
01-75
;

09.92 ▸=> reading measured value block, display group 004, Page
01-159
.

Checking internal resistance

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

Connect multimeter to valve to measure resistance
Specification: 7 ... 11 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:

Replace idling stabilisation valve.

Mechanical checking

Remove idling stabilisation valve

Check piston slide -arrow- for scoring (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 => Page
01-70
and actuate idling stabilisation valve -N71.
Check 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):

Replace idling stabilisation valve.

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

Checking activation

Push back protective cap at connector
Start final control diagnosis => Page
01-70
and actuate idling stabilisation valve -N71.

Connect voltage tester V.A.G 1527 B as follows:

Idling stabilisation / valve / Contact · Measure to
1 · Engine earth

The LED must flash.

Connect voltage tester V.A.G 1527 B as follows:

Idling stabilisation / valve / Contact · Measure to
2 · Battery positive

The LED must illuminate.

If the specified values are not obtained:

With the ignition off, use adapter V.A.G 1598/12 to connect test box V.A.G 1598 A to engine control unit connector D (control unit remains disconnected) => Page
24-17
.

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

Connector / contact · Test box V.A.G 1598 A / socket
1 · 11
2 · 7

Rectify any open/short circuit as necessary.

=> "Current Flow Diagrams, Electrical Fault Finding and Fitting Locations" binder

If activation and wiring are OK, but idling stabilisation valve does not react, valve is seized up. Replace idling stabilisation valve.
If the wiring is OK, but the valve is not activated, replace the engine control unit => Page
24-20
.