1997 AUDI A4 engine

28-38

Display Group 23 -Ignition- Knock control

Driving mode
Read measuring value block
23
Indicated on display

xx.x RPM x.x %
xx.x KW
xx.x KW



1 2
3 4
Display fields
Specified value
Evaluation


Ignition timing retard via knock control:
cylinder 4 0...12 KW
(crankshaft
angle)
Page 28
-40




Ignition timing retard via knock control:
cylinder 3
0...12 KW
(crankshaft
angle)
Page 28
-40



Engine load 15 - 175 %

Engine speed RPM
750 - 6800 RPM

Note:
The displayed digit values in display fields 3 and 4 reflects the actual "ignition timing retard" via knock control from cylinders 3
and 4. The ignition timing retard occurs via KW (crankshaft angle).
Pa
ge 43 of 64 I
gnition s
ystem, checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.28.1

28-39

Display Group 24 -Ignition- Knock control

Driving mode
Read measuring value block
24
Indicated on display

xx.x RPM x.x %
xx.x KW
xx.x KW



1 2
3 4
Display fields
Specified value
Evaluation


Ignition timing retard via knock control:
cylinder 6 0...12 KW
(crankshaft
angle)
Page 28
-40




Ignition timing retard via knock control:
cylinder 5
0...12 KW
(crankshaft
angle)
Page 28
-40



Engine load 15 - 175 %

Engine speed RPM
750 - 6800 RPM

Note:
The displayed digit values in display fields 3 and 4 reflects the actual "ignition timing retard" via knock control from cylinders 5
and 6. The ignition timing retard occurs via KW (crankshaft angle).
Pa
ge 44 of 64 I
gnition s
ystem, checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.28.1

28-40
Evaluation display groups 20/21/22/23/24, - Ignition timing angle retard Indicated on display
Malfunction cause
Corrective action
All cylinders greater
than 12 KW
Knock sensor faulty- Check knock sensor Page 28
-41
.


Corroded connection

Knock sensor incorrect
tightening torque - Loosen and tighten knock sensor with 20 Nm (15 ft lb)

Components on engine
loose - Tighten components

Low fuel grade- Change fuel grade
One cylinder deviates
clearly from others Corroded connection- Check knock sensor Page 28
-41
.


Engine damage
Repair Manual, 2.7 Liter V6 5V BiTurbo Engine Mechanical, Engine
Code(s): APB, Repair Group 15, Cylinder head removing, check compression pressure
- Check compression pressure:


Components on engine
loose - Tighten components
Pa
ge 45 of 64 I
gnition s
ystem, checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.28.1

28-41

Knock Sensor (KS) 1 -G61 and Knock
Sensor (KS) 2 -G66, checking


Notes:

It is not possible to carry out an electrical test of
the knock sensors themselves.
To ensure that the knock sensors function
properly it is important to keep exactly to the
specified tightening torque of 20 Nm (15 ft lb)
Use only gold-plated terminals when repairing
the terminals in the plug connectors for the
knock sensors.
Check for corrosion in connection between
knock sensor and wiring harness.

Checking knock sensors

Note: - Disconnect harness connector for relevant knock sensor in engine
compartment.
Component location overview Page 24
-5 .
In order to reach the connector for the knock sensor for cylinder bank
2, first remove the bolts securing the coolant reservoir and move the
Pa
ge 46 of 64 I
gnition s
ystem, checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.28.1

28-42


If there is a connection between the terminals.
Notes:
If there is no short circuit
Checking wiring between knock sensors and engine control module - Check for short circuits between all three terminals in knock sensor
connector (terminals 1 + 2, 1 + 3 and 2 + 3).
Specified value: There must be no contact between the wires (infinite
). - Replace knock sensor.
In order to reach the knock sensors, first remove the air duct Page 24
-43
.
Use special tool 3247 to remove the knock sensors.
- Check wiring for knock sensors.

- Connect VAG1598/31 test box to wiring harness for engine control
module. Do not connect to the engine control module itself Page 24
-
20
.
Pa
ge 48 of 64 I
gnition s
ystem, checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.28.1

28-43


- Check wiring connection from relevant sensor connector to...

- ....Engine Control Module (ECM) for open circuit and/or short to B+ or
Ground (GND).
Pa
ge 49 of 64 I
gnition s
ystem, checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.28.1

28-46

- Operate starter for few seconds.
The diode test lamp should blink briefly once
every two engine revolutions.

Note:
Diode test lamps with a low current draw
continue to glow faintly between impulses from
the engine control module (rather than going out
completely) and become much brighter when
receiving an impulse.
If the diode test lamp does not flash, test the
voltage supply.

Checking voltage supply for Hall sensor

- Disconnect harness connector from relevant Hall
sensor.

- Switch ignition on.
Pa
ge 53 of 64 I
gnition s
ystem, checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.28.1

28-47


Checking signal wire for Hall sensor
Checking Ground (GND) wire for Hall sensor: - Connect multimeter (Fluke 83 or equivalent) (voltage measurement
range) between engine Ground (GND) and socket 1 of connector.
Specified value: approx. 5 V
- Connect multimeter (Fluke 83 or equivalent) (voltage measurement
range) between engine Ground (GND) and socket 2 of relevant
connector.
Specified value: approx. battery voltage
- Connect VAG1598/31 test box to wiring harness for engine control
module. Do not connect to the engine control module itself Page 24
-
20
.

- Connect multimeter (Fluke 83 or equivalent) (resistance measurement
range) between socket 3 on connector and engine Ground (GND).
Specified value: Continuity
Resistance in wiring: max. 1.5 Ohms
Pa
ge 54 of 64 I
gnition s
ystem, checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.28.1