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Checking engine speed sender > < Testing control unit input values

A4 Mk1

Motronic Fuel Injection and ignition system (4-cyl.) 07.96ä
Testing control unit input values
Checking control unit power supply

Test conditions

  • ● Battery voltage OK.
  • ‒ Read measured value block, Display Group 3, engine stopped
 
→ Indicated on display:
Read measurement block 3    ⇒
    860 rpm    12.760 V    18.65 C    17.85C
  • ‒ Check display in display zone 2.
  • Specification: approx. battery voltage

If the specification is not obtained:

  • ‒ Connect test box V.A.G 1598/22 to wiring harness for engine control unit
    .
  • ‒ Connect multimeter between the following contacts on the test box to test the voltage:

Test box, socket.

Specification

Ignition off

3 + 2

approx. battery voltage

Ignition on

1 + 2

approx. battery voltage

If the specified values are not obtained:

  • ‒ Check the wiring.

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

Checking engine speed sender > < Testing control unit input values