audi Workshop Repair Guides

Audi Workshop Service and Repair Manuals

Checking mechanical EGR valve > < Checking EGR
MPI fuel injection and ignition system
Checking EGR
Checking EGR valve -N18

Special tools,
testers and 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 1598/12
  • ◆ VAS 5051 with VAS 5051/1
  • or
  • ◆ V.A.G 1551 with V.A.G 1551/3 A

Fitting location => Fitting locations overview, Page 24-6

Note:

Checking operation=> Reading measured value block display group 017, Page 01-143.

Test requirements:

  • ● Final control diagnosis has been performed

Checking internal resistance

  • ‒ Pull connector off EGR valve -N18
 
V26-0708
  • ‒ → Connect multimeter to valve to measure resistance
    • ‒ Specification: 25 ... 35 ω
  • ‒ If the specification is not attained, renew EGR valve -N18.

Checking power supply

  • ‒ Pull connector off EGR valve -N18
 
V96-0749
  • ‒ → Connect voltage tester V.A.G 1527 B as follows:

Connector
Contact

Measure against

1

Engine earth

  • ‒ Start final control diagnosis and actuate fuel pump relay -J17.
    • ‒ The LED should light up.

If the LED does not light up:

 
A97-0022
  • ‒ Carry out the following tests (marked with dots):
  • ● → Check fuse S229 (in fuse holder, position 29).
 
V96-0749
  • ● → Check for open circuit between contact 1 on connector and fuse in fuse holder .

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

  • ● Check fuel pump relay => Page 24-43

Checking actuation

 
V96-0749
  • ‒ → Connect voltage tester V.A.G 1527 B to contacts 1 and 2 of the connector.
  • ‒ Start final control diagnosis => Page 01-75 and actuate EGR valve -N18.
    • ‒ The LED should flash.
 
A87-0016

If the LED lamp does not flash or if it lights up continuously:

  • ‒ → With the ignition switched off, use adapter V.A.G 1598/12 to connect test box V.A.G 1598 A to connector D only of engine control unit (control unit remains disconnected) => Page 24-17.

 
V96-0749
  • ‒ → Check for open circuit and short to positive or earth in the following wiring connections:

Connector
Contact

Test box V.A.G 1598 A
Socket

2

14

  • ‒ Rectify short circuit or open circuit if necessary.

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

  • ‒ If the wiring is OK, fit a new engine control unit => Page 24-20.

Checking mechanical EGR valve > < Checking EGR