ignition AUDI A4 1998 B5 / 1.G ATQ Engine Ignition System Checking Owner's Manual

28-39


Display fields

1 2 3 4
Display group 024: Ignition -knock control in driving operation
Display xxxx/min xxx.x %
xx.x KW
xx.x KW
Indicated Engine speed
(RPM) Engine
load Ignition angle retardation cylinder 5
via knock control
Knock sensor control Ignition angle retardation cylinder 6
via knock control
Knock sensor control
Specified
value xxxx/min 12 to 100
% 0 to 12 KW
0 to 12 KW
Notes Evaluation Page 28
-40

Note:
The number values indicated in display fields 3 and 4 represent actual ignition angle retardation via knock control of cylinders
5 and 6. Ignition angle retardation occurs in KW (crankshaft degrees) toward retardation.
Pa
ge 44 of 65 I
gnition s
ystem, checkin
g
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU05.28.1

28-40
Evaluation display groups 020/021/022/023/024 - ignition angle retardation
Indicated on display
Possible cause
Corrective action
All cylinders more than 12 KW
Knock sensor faulty- Check knock sensor Page 28
-41

Harness connector corroded
Knock sensor incorrect
tightening torque - Loosen knock sensors and tighten to 20
Nm
Engine accessories loose- Secure engine accessories
Poor fuel quality- Change fuel quality
(see operating instructions)
One cylinder deviates significantly from
the others Harness connector corroded- Check knock sensor Page 28
-41

Engine damage
Repair Manual, Engine Mechanical,
Repair Group 15 - Check compression pressure:

Engine accessories loose- Secure engine accessories
Pa
ge 45 of 65 I
gnition s
ystem, checkin
g
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU05.28.1

28-47

Note:
Voltage testers do not go out completely during
low current pick-up between activations by the
ECM, but rather continue to glow a little and then
get significantly brighter during activation.
If LED does not blink:

Checking voltage supply

- Disconnect connector at respective Camshaft
Position (CMP) sensor.

- Switch ignition on.

- Connect multimeter for voltage measurement as follows:Harness connector
Terminal
Measure to
1 Engine Ground (GND)

Specification: about 5 V
Pa
ge 52 of 65 I
gnition s
ystem, checkin
g
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU05.28.1

28-56
Evaluation display group 014, display field 3 and display group 015 and 016, display fields 1, 2 and 3
Indicated on
display
Possible cause
Corrective action
greater than 15

spark plug defective
spark plug connector defective
Ignition coil or power output stage faulty- Check spark plugs and ignition wires with connectors.
- Check ignition coils and power output stages Page
28
-7


Fuel injector faulty- Check fuel injectors Page 24
-36


Poor compression of one or more
cylinders
Repair Manual, Engine Mechanical, Repair Group
15 - Check compression pressure:
Pa
ge 65 of 65 I
gnition s
ystem, checkin
g
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU05.28.1