SEAT Workshop Service and Repair Manuals

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

• ◆ Fault reader V.A.G 1551 or vehicle system tester V.A.G 1552 with cable V.A.G 1551/3
• ◆ Test box V.A.G 1598/31
• ◆ 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 must be OK
• ● → Fuses No. 13 and 14 must be OK.

Test sequence

• ‒ First check the activation of the injectors via final control diagnosis .

Note:

To perform electrical check of No. 2 and 3 cyl. injectors/wiring, the manifold upper part must be removed.

If one or more injectors do not click:

Checking voltage supply

• ‒ Pull connectors off injectors.

• ‒ → Connect diode test lamp to contact 1 and earth of relevant injector connector.
• ‒ Operate the starter and check the voltage supply for the injector.
      The LED must light up

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

Checking activation and voltage supply

• ‒ Pull connectors off injectors.
• ‒ Connect the diode test lamp V.A.G 1527 to the connector contacts of the injector to be tested using adapter cables from V.A.G 1594.
• ‒ Operate starter and check the activation for the injector.
      The LED must flicker

Note:

The flickering is difficult to see.

If the LED does not flicker:

• ‒ Switch off ignition.
• ‒ Remove battery.
• ‒ → Connect test box V.A.G 1598/31 to control unit wiring harness. The engine control unit remains disconnected.

• ‒ → Check the wiring between the test box and connector for open circuit, short circuit to earth or positive using current flow diagram:
      Injector 1: contact 2+socket 96
      Injector 2: contact 2+socket 89
      Injector 3: contact 2+socket 97
      Injector 4: contact 2+socket 88
      Wire resistance: max. 1.5 ω

If no fault is detected in the wiring:

Checking resistance of injectors

• ‒ → Check resistance of injector between contacts.
      Specification: 14...18 ω

Note:

The resistance figures are valid for approx. 20 °C. At higher temperatures the resistance figures will increase.

If the specification is not attained:

• ‒ Renew defective injector
• ‒ Erase fault memory to put learnt values in a neutral setting => Page 01-17, Interrogating and erasing learnt values.

If the resistance values are OK and no wiring fault has been detected:

• ‒ Renew engine control unit => Page 24-108.

Check injectors for leaks and quantity injected

Special tools, workshop equipment, test and measuring appliances and auxiliary items required

• ◆ V.A.G 1348/3 Remote control
• ◆ V.A.G 1348/3-2 Adapter
• ◆ V.A.G 1602 Calibration tester
• ◆ V.A.G 1594 A Adapter set
• ◆ V.A.G 1598/31 Test box

Test conditions

• ● The fuel pressure must be in order, checking
  => Page 24-74.

Test sequence

• ‒ Remove battery.

• ‒ → Connect test box V.A.G 1598/31 to control unit wiring harness. The engine control unit remains disconnected.
• ‒ Remove intake manifold upper part.
• ‒ Pull connectors off injectors.
• ‒ Remove fuel rail securing bolts.
• ‒ Pull off vacuum hose from fuel pressure regulator.
• ‒ Pull hose for air shrouded injectors off air pipe (, item 4).
• ‒ Lift fuel rail with injectors off intake manifold and support it.
• ‒ Install battery and loosely attach battery terminal clamps.
• ‒ Bridge test box sockets 1 and 65 with adapter cables from adapter set V.A.G 1594.

Note:

This step serves only to run the fuel pump when the engine is not running.

• ‒ Switch ignition on.

Checking for leaks

• ‒ Check injector for leaks (visual check). Only 1 to 2 drops per minute must emit from each valve when fuel pump is running.

If the fuel loss is greater:

• ‒ Switch off ignition and renew leaking injector.
• ‒ Erase fault memory to put learnt values in a neutral setting => Page 01-17, Interrogating and erasing learnt values.

Note:

Always renew seals.

Checking injected quantity

Test conditions

• ● Test box V.A.G 1598/31 still connected and test box sockets 1 and 65 bridged with adapter cables from test aid set V.A.G 1594.

• ‒ Insert injector to be checked in a measuring glass of tester for injected quantity V.A.G 1602.
• ‒ → Connect one contact of the injector to be tested to engine earth using auxiliary cables from V.A.G 1594.
• ‒ Connect the second injector contact with auxiliary cable to remote control V.A.G 1348/3 using adapter cable V.A.G 1348/3-2.
• ‒ Connect crocodile clip to battery (+).
• ‒ Switch ignition on; the fuel pump must run.
• ‒ Operate remote control V.A.G 1348/3 for 30 seconds.
• ‒ Repeat check on the other injectors. To do this use new measuring beakers.
• ‒ After all injectors have been activated, place the measuring containers on a level surface and compare the quantity injected.
      Specification: 85...105 ml per injector

If the measured values of one or more injectors are above or below the prescribed specifications:

• ‒ Renew defective injector
• ‒ Erase fault memory to put learnt values in a neutral setting => Page 01-17, Interrogating and erasing learnt values.

Perform installation of injectors in reverse order. When doing this note the following:

• ◆ Renew O-rings on all injectors and lightly moisten with clean engine oil.
• ◆ Insert injectors vertically and in the correct position into the fuel rail and secure with retaining clips.
• ◆ Fit fuel rail with secured injectors onto intake manifold and press in evenly.