Volkswagen Workshop Service and Repair Manuals

▸07.93

Note:

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

• ‒ → Pull injector connector -1- off fuel manifold -2-.

Checking voltage supply

• ‒ → Pull off plug of cold start valve (N17) and connect diode test lamp V.A.G 1527 with aux. cables from V.A.G 1594.

• ‒ → Pull connector off coolant temperature sender (G62).
• ‒ → Set Digital potentiometer V.A.G 1630 -side A- to 3.8 kω
  (corresp. approx. 10 °C) and connect to above connector using aux. cables from V.A.G 1594.
• ‒ Operate starter.
       The LED must light up for approx. 1...4 seconds (Repeatedly starting engine reduces LED light up time).
• ‒ Set Digital potentiometer to 2.6 kω (corresponds to approx. 20 °C).
• ‒ Operate starter.
       The LED must not light .

Otherwise:

• ‒ Reconnect to cold start valve connector.
• ‒ Carry out electrical check, test step 3
  , if necessary renew Digifant control unit (J169).

Checking cold start valve (N17)

• ● Voltage supply OK.
• ● Cold start valve connector attached.
• ● Digital potentiometer connected to coolant temperature sender connector.

• ● Connector for injectors disconnected from fuel manifold.

• ‒ → Set Digital potentiometer V.A.G 1630 -Side A- to 3,8 kω.

• ‒ → Remove cold start valve and hold in a measuring container.
• ‒ Operate starter.
       The cold start valve must spray uniformly for approx. 1...4
       seconds.
• ‒ Dry off cold start valve nozzle.
       The cold start valve must not drip for one minute or show               signs of external dampness.