Checking power supply for control unit: Audi 2.0 (ABK)

Special tools and workshop equipment required

V.A.G 1526 A
V.A.G 1527 B
V.A.G 1594 A
V.A.G 1598 A with V.A.G 1598/9
VAS 5051 with VAS 5051/1

or

V.A.G 1551 with V.A.G 1551/3 A

Digifant control unit is supplied with power by way of current supply relay for Digifant control unit -J176.

Note:

Fitting location of current supply relay for Digifant control unit -J176: On auxiliary relay carrier at front left beneath dash panel, position 14

Test sequence

Reading measured value block 3
⇒
1
2
3
4
Read measured value block, Display group 003 => Page
01-53
.
Check display in zone 4.
Specification: approx. battery voltage

If reading does not match specification:

Checking power supply

With ignition switched off, use adapter V.A.G 1598/9 to connect test box V.A.G 1598 A to connector of font=symbol charset=fontspecific code=101font=symbol charset=fontspecific code=110 TeX='\nu ' descr='[nu]'γfont=symbol charset=fontspecific code=105 TeX='\iota ' descr='[iota]'font=symbol charset=fontspecific code=110 TeX='\nu ' descr='[nu]'font=symbol charset=fontspecific code=101control unit only (not to control unit) => Page
24-14
.

Connect up multimeter for voltage measurement as follows.

Test box V.A.G 1598 A / Socket · Measure to
19 · Engine earth

Switch on ignition.
Specification: approx. battery voltage

If reading does not match specification:

Use current flow diagram to check wiring between connector of Digifant control unit and current supply relay for Digifant control unit -J176.

If wiring is OK:

Check power supply of current supply relay for Digifant control unit -J176 => Page
28-33
.
Check actuation of current supply relay for Digifant control unit -J176 => Page
28-34
.
If power supply and actuation of current supply relay are OK, replace relay.

Checking earth supply

Connect up multimeter for voltage measurement as follows.

Test box V.A.G 1598 A / Socket · Measure to
1 · Battery positive
28 · Battery positive
35 · Battery positive

Specification: approx. battery voltage in each case

If readings do not match specifications:

Use current flow diagram to check wiring between connector of Digifant control unit and earth points.
Eliminate open circuit in wiring if necessary.