2001奥迪A4保养与维修手册（三）.pdf

B
A –Disconnect power supply relay -2-.
C

2 3 4
A24–0430
4
– Carry out the following tests (marked with dots):
1 Check the wiring of relay carrier, electronics box, plenum chamber,
position 2, contact 8, to connector of ignition coil contact 1.
2
Check power supply relay for Motronic -J271 ⇒ Page 28-14.
3
7
8
9
6 5 A24–0298
28-11
Checking actuation of power output stages
1 –Unplug connectors from all injectors.
Note:
2 It is important to ensure that no fuel is injected during the test, as this
would damage the catalytic converter. Therefore, the connectors on
the injectors must be unplugged.
–Unplug 4-pin connector -1- from ignition coil -2-.

A28–0050
– Connect voltage tester 1527 B to contacts 2 and 3 of the con-
nector.
–Operate starter briefly.
♦ The diode test lamp should flash (very brief flashes).
1 4
A24–0094
28-12
If LED does not flash:
– Connect test box 1598/31 to wiring harness for engine control
unit; do not connect the engine control unit ⇒ Page 24-17.
– Check for open circuit and short to positive or earth in the following
wiring connections:
Connector Test box 1598/31
1 4 contact Socket
A24–0094
3 (cyl. 1) 102
3 (cyl. 2) 95
3 (cyl. 3) 103
3 (cyl. 4) 94
– Rectify any open/short circuit as necessary.
If no wiring fault is detected:
– Replace ponent ignition coil with output stage.
28-13
1526 A 1594 A Checking power supply relay
for Motronic system -J271
Special tools and workshop equipment
required
♦ 1526 A
♦ 1594 A
♦ 1598/31
1598/31
G24–0020
28-14
Note:
The power supply relay for Motronic -J271 supplies the ignition coils
with output stages as well as the engine control unit on Pin 121 with
power.
Test sequence
– Remove engine cover -arrows-.

A10–0661
1 –Unplug 4-pin connector -1- from ignition coil -2-.
2
A28–0050
28-15
– Connect multimeter as follows