Checking current supply relay for Digifant control unit -J176 — AUDI

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

Note:

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

Checking operation

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 voltage tester V.A.G 1527 B as follows.

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

Switch on ignition.
Current supply relay for Digifant control unit -J176 (in auxiliary relay carrier at front left beneath dash panel, position 14) must click ...
... and LED must light

A - If relay clicks, but LED does not light:

Pull out current supply relay.

Check for open circuit in the following wiring.

Auxiliary relay carrier at front beneath dash panel on left, / position 14 / Contact · Test box V.A.G 1598 A / / / / Socket
6 · 19

Eliminate open circuit in wiring if necessary.

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

If wiring is OK:

Replace current supply relay for Digifant control unit -J176.

B - If LED does not light and relay does not click:

Checking power supply

Pull out current supply relay.

Connect up multimeter for voltage measurement as follows.

Auxiliary relay carrier at front beneath dash panel on left, / position 14 / Contact · Measure to /
2 · Engine earth
4 · Battery positive

Specification: approx. battery voltage in each case

Connect up voltage tester V.A.G 1527 B as follows.

Auxiliary relay carrier at front beneath dash panel on left, / position 14 / Contact · Measure to /
8 · Engine earth

Switch on ignition.
Specification: approx. battery voltage

If readings do not match specifications:

Use current flow diagram to check for open circuit/short circuit in wiring.

If no fault is found in wiring:

Checking actuation

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
.
Check for open circuit in the following wiring.

Auxiliary relay carrier at front beneath dash panel on left, / position 14 / Contact · Test box V.A.G 1598 A / / / / Socket
9 · 7

Eliminate open circuit in wiring if necessary.

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

If no fault is found:

Replace engine control unit => Page
24-17
.

Note:

After replacing engine control unit, control unit and throttle valve potentiometer must be matched => Page
24-98
.