Checking cold start valve -N17 — AUDI

Special tools and workshop equipment required

V.A.G 1526 A
V.A.G 1527 B
V.A.G 1594 A
V.A.G 1598 A
V.A.G 1598/3
V.A.G 1630
VAS 5051 with VAS 5051/1 and VAS 5051/2

or

V.A.G 1551 with V.A.G 1551/1
Measuring unit, fuel-resistant

Fitting location => Fitting locations overview, Page
25-5

Checking internal resistance

Pull connector off cold start valve.
Connect multimeter to injector to measure resistance.
Specification: 8 ... 15 ω

If the specification is not obtained:

Replace the cold start valve

If the cold start valve does not react with final control diagnosis:

Checking power supply

Test requirements:

Fuse S75 in brown holder in electronics box in passenger footwell OK

Pull connector off cold start valve.

Connect up multimeter as follows to measure voltage.

Connector / Contact · Measure to
1 · Engine earth

Switch the ignition on.
Specification: approx. battery voltage

If the specification is not obtained:

Eliminate open circuit or short circuit using the current flow diagram.

If the specification is obtained:

Check actuation.

Checking actuation

Test requirements:

Idling switch OK, testing =>Page
25-37
.

Connect up voltage tester V.A.G 1527 B between contacts 1 and 2.
Initiate final control diagnosis and actuate cold start valve -N17 => Page
01-32
.

Slightly open throttle valve.
The LED should flash.

If LED does flash:

Replace the cold start valve

If LED does not flash:

With the ignition switched off, use adapter V.A.G 1598/3 to connect test box V.A.G 1598 A to plug connection of engine control unit (control unit remains disconnected) => Page
25-9
.

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

Connector / Contact · Test box V.A.G 1598 A / Socket
2 · 16

Rectify any open/short circuit as necessary.

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

If the wiring is OK and no activation is carried out:

Replace engine control unit => Page
25-12
.

Checking spray pattern, injection point and absence of leaks of cold start valve

Unplug connector -arrow 1- from output stage.

Unplug air intake elbow at throttle valve elbow
Unplug connector on coolant temperature sender.

Connect side A of digital potentiometer V.A.G 1630 with the disconnected connector of the coolant temperature sender.
Adjust side A of the V.A.G 1630 to 15 kω .

Remove cold start valve with connected petrol line from intake manifold and hold into a measuring glass.
Operate starter.
The cold start valve should eject fuel intermittently for approx. 8 seconds in an even taper.

Dry off the cold start valve at the nozzle.
No drip should drop from the cold start valve within 1 minute. The cold start valve must also not be moist on the outside.