Testing Motronic current supply relay -J271 - Vehicles model year 2000 > — AUDI

APP
Special tools and workshop equipment required

V.A.G 1526 A
V.A.G 1594 A
V.A.G 1598/31

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

Note:

The Motronic current supply relay -J271 supplies voltage to the ignition coils with output stages and to the engine control unit (pin 121).

Test sequence

Unplug 4-pin connector -1- from one ignition coil -2-.

Connect multimeter (voltage measurement range) as follows:

Connector / Contact · Measure against
1 · Engine earth

Switch on ignition.
Specification: approx. battery voltage

If the specification is not attained:

Unplug current supply relay -2- (located under cover on left side of bulkhead).

Note:

To remove protective cover on TT Roadster vehicles, disengage and move down relay carrier on bulkhead. If necessary, also unplug connector on air mass meter.

Test for open circuits in the following wiring connection according to current flow diagram:

Relay carrier under cover on left side of bulkhead / Contact · Connectors on ignition coils / / Contact
2 · 1

Rectify any open circuit as necessary.

If the wiring is OK:

Test supply voltage for Motronic current supply relay -J271 => Page
28-14
.

Test activation of Motronic current supply relay -J271 => Page
28-16
.

Checking voltage supply

Switch off ignition.
Unplug current supply relay -2- (located under cover on left side of bulkhead).

Connect multimeter (voltage measurement range) as follows:

Relay carrier below cover on left side of bulkhead / Contact · Measure against /
1 · Engine earth
3 · Engine earth

Specification: approx. battery voltage

If the specification is not attained:

Carry out the following tests (marked with dots):

Check fuse S10 (in fuse carrier, plug-in position10).

Check fuse S134 (110 A) in main fuse box on battery.
Test for open circuit in wiring from battery + (terminal 30) via fuse S134 and fuse 10 to Motronic current supply relay -J271 (under cover on left side of bulkhead):

=> Current flow diagrams, Electrical fault finding and Fitting locations

Checking activation

Switch off ignition.
Unplug current supply relay -2- (located under cover on left side of bulkhead).

Connect multimeter (voltage measurement range) as follows:

Relay carrier below cover on left side of bulkhead / Contact · Measure against /
5 · Battery positive

Switch on ignition.
Specification: approx. battery voltage

If the specification is not attained:

Switch off ignition.
Connect test box V.A.G 1598/31 to wiring harness for engine control unit. Do not connect to the engine control unit itself.
=> Page
24-20
.

Test for open circuit and short to positive or earth in the following wiring connections:

Relay carrier below cover on left side of bulkhead / Contact · Test box V.A.G 1598/31 / Socket
5 · 21

Rectify any open/short circuit as necessary.

If no fault is found:

Fit a new current supply relay -J271.