Testing cold start valve -N17 — AUDI

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
Test box V.A.G 1598/18

Testing internal resistance

Note:

The cold start valve injects only at coolant temperatures below 15 °C.

Pull connector off cold start 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: 8 ... 15 ω

If the specification is not obtained:

Replace the cold start valve

Testing voltage supply and actuation

Test requirements:

Fuse S75 in red holder in electronics box in passenger footwell OK
Start signal present; testing => Page
24-113
.

Unplug connectors from all injectors.
Pull connector off cold start valve.

Connect voltage tester V.A.G 1527 B as follows with auxiliary leads from V.A.G 1594 A:

-N17 connector / Contact · Measure to
1 · Engine earth

Switch the ignition on.
The LED should light up.

If the LED does not light up:

Eliminate open circuit in wiring according to current flow diagram

Connect voltage tester V.A.G 1527 B between contacts 1 and 2 of the connector of the cold start valve using auxiliary wires from V.A.G 1594 A.

Pull connector off coolant temperature sender -G62 -arrow-
Operate starter.
The LED should come on for 1 ... 4 seconds

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

-N17 connector / / Contact · Test box / V.A.G 1598/18 / socket
2 · 6

If the wiring is OK, but the valve is not actuated, renew the Digifant control unit => Page
24-18
.

Notes:

After replacing the Digifant control unit , it is necessary to adapt the control unit and throttle valve potentiometer to each other=> Page
24-92
.
After replacing the Digifant control unit on vehicles fitted with an automatic gearbox, it is necessary to adapt the automatic gearbox control unit and the throttle valve potentiometer to each other => Page
24-93
.

Testing spray pattern, injection time and absence of leaks of cold start valve

Unplug connectors from all injectors.

Pull plug off coolant temperature sender -G62 -arrow-.

Detach the cold start valve with the fuel line connected from the intake manifold.
Detach fuel supply line from fuel manifold.
Turn the cold start valve with the fuel supply pipe and hold the cold start valve in a measuring glass.

Connect the fuel supply pipe to the fuel manifold again.
Operate starter.
The cold start valve should eject a pulsating spray on a uniform cone for 1 ... 4 seconds

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.