Volkswagen Workshop Service and Repair Manuals

Special tools, workshop equipment, testers, measuring instruments and auxiliary items required

• ◆ Test box V.A.G 1598/22
• ◆ Hand multimeter V.A.G 1526 or multimeter V.A.G 1715
• ◆ Diode test lamp V.A.G 1527
• ◆ Adapter set V.A.G 1594
• ◆ Current flow diagram

Check conditions

• ● Engine speed sender must be OK, checking .
• ● Fuel pump relay OK

• ● → Fuse 32 must be OK.

Checking activation and voltage supply

• ‒ Remove intake manifold upper part
  .
• ‒ Pull plug off all injectors.

• ‒ → Connect diode test lamp V.A.G 1527 using aux. cables from V.A.G 1594 to connector contacts of Cyl. 1.
• ‒ Operate the starter and check the voltage supply for No. 1 cylinder injector.
       The LED must flicker
• ‒ Repeat check at the injector connectors for Cyls. 2...4.

If the LED does not flicker on any cylinder:

• ‒ → Connect diode test lamp to Cyl. 1 connector, contact 1 and earth.
• ‒ Operate starter.
       The LED must light

If the LED does not light up:

• ‒ Switch off ignition
• ‒ Check wire between 2 pin connector contact 1 and fuel pump relay (J17) for open circuit using current flow diagram.
       Wire resistance: max. 1.5 ω

If the LED flickers on one or several cylinders:

• ‒ → Connect test box V.A.G 1598/22 to wiring harness for control unit.

• ‒ → Check wiring between test box and connector for open circuit according to current flow diagram.
       Injector 1: Contact 2+socket 73
       Injector 2: Contact 2+socket 80
       Injector 3: Contact 2+socket 58
       Injector 4: Contact 2+socket 65
       Wire resistance: Max.1.5 ω
• ‒ Additionally check wires for short to one another.
       Specification: ∞ω
• ‒ Check wiring between connector contacts 1 of injectors for open circuit to one another.
       Wire resistance: Max. 1.5 ω

• ‒ If no fault is found in the activation or voltage supply, check resistance of injectors.

Checking resistance of injectors

• ‒ → Check resistance of injectors individually
       Specification: 14...17 ω(at 20° C)

When the engine is warm the resistance will be approx. 4...6 ωhigher.

• ‒ If the measured value is not as specified, renew the injector.

Checking spray pattern and for leaks

Special tools, workshop equipment, testers, measuring instruments and auxiliary items required

• ◆ → Digital potentiometer V.A.G 1630

• ◆ → Fuel-quantity comparison meter V.A.G 1348/2B

Test sequence

• ‒ Remove intake manifold upper part
  => Page 24-16 .

• ‒ Remove fuel rail complete with injectors.
• ‒ → Hold injectors in the measuring appliance V.A.G 1348/2B.

• ‒ → Pull 4 pin connector -1- off coolant temperature sender (G62) -2-.

• ‒ → Set digital potentiometer V.A.G 1630 -side A- to 15 kωand using aux. cables from V.A.G 1594 connect to contacts 1+3 of disconnected plug.
• ‒ Pull plug off ignition coils.
• ‒ Operate starter (2nd person required). The injectors must pulsate and spray in accordance with firing order.
• ‒ Switch off ignition and check injectors for leaks. No more than
       2 drops/min
  may leak from each injector.

Note:

When installing the injectors ensure that the O rings

are not damaged.