fuel AUDI A8 1998 D2 / 1.G AHA Engine Motronic Ignition System Workshop Manual

28-1
Motronic ignition system Technical data, spark plugs

Engine code
AHA

Engine idle RPM

Idle RPM cannot be adjusted, is corrected by Idle Air Control (IAC) 620 - 740 RPM
(all-wheel drive)
740 - 860 RPM
(front-wheel drive)
RPM limit
Operates by shutting off fuel injectors approx. 6500 RPM
Ignition timing
Ignition timing cannot be adjusted; it is determined by the Engine Control Module (ECM)
Firing order 1-4-3-6-2-5
Spark plugs Tightening torque 30 Nm (22 ft lb)
Part No. 1) 101 000 035 HJ (NGK)
Manufacturer's code
(if applicable) BKR 6 EKUB (NGK)

Electrode gap - mm 1.6 mm

Maintenance interval Owner's Manual

Pa
ge 1 of 34 Motronic i
gnition s
ystem
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU03.28.1

28-11
Evaluation of display groups 22, 23 and 24 Display groups: 22, 23 and 24
Possible malfunction
cause
Corrective action
Display fields: 3, 4


All cylinders retarded more than
10 (crankshaft)
Knock sensor faulty- Continuation page 28
-12

Connector corroded
Knock sensor
incorrectly torqued - Loosen knock sensor and tighten to 20 Nm (15 ft lb)
Components loose on
engine - Tighten components
Poor fuel quality- Change fuel
Value for one cylinder different
from the others Connector corroded- Continuation page 28
-12

Engine damage- Check compression Repair Manual, 2.8 Liter V6 5V
Engine Mechanical, Repair Group 15

Components loose on
engine - Tighten components
Pa
ge 14 of 34 Motronic i
gnition s
ystem
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU03.28.1

28-20
Evaluation of display groups 15 and 16 Display groups: 15
and 16


Display fields: 2 and
3
Possible malfunction cause
Corrective action
greater than 5

Ignition coil faulty
Spark plug connector faulty
Spark plug faulty
Power output stage for
ignition coil faulty - Check ignition coils -N-, -N128- and -N158- with power output
stage -N122 page 28
-21



Fuel injector faulty
Not enough fuel- Check fuel injectors page 24
-102
- Check fuel in tank
Pa
ge 24 of 34 Motronic i
gnition s
ystem
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU03.28.1

28-21

Ignition coils and power output stage,
checking


Notes:

The ignition coils and power output stage are
one component.
Measuring the primary resistance of the ignition
coils is not possible.
Measure secondary resistance first with ignition
wires connected to the ignition coil via the spark
plug connector of the respective cylinder (with
this method the interference resistances of the
ignition cables are also measured).
Component locations page 24
-1

Required special tools and test equipment

Multimeter US1119 (Fluke 83 or equivalent)
VW1594 connector test kit

Test conditions
No fuel injector malfunction stored in DTC
Pa
ge 25 of 34 Motronic i
gnition s
ystem
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU03.28.1

28-22

Checking

- Check DTC memory page 01
-16
.

There must be no malfunctions stored

- If DTC memory is not clear (malfunctions
recognized):

- Make necessary repairs and erase DTC
memory.

- Stop engine and start engine again.

- Road test.

- Check and erase DTC memory again.

- By briefly disconnecting fuel injector connectors
with engine running, check which cylinder is
misfiring, or not firing at all.
A misfiring cylinder can also be isolated by
examining the spark plugs (for a carbon-fouled
plug).

-
Interchange spark plug with one from cylinder
Pa
ge 27 of 34 Motronic i
gnition s
ystem
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU03.28.1