ignition AUDI A4 1998 B5 / 1.G ATQ Engine Ignition System Checking User Guide

28-12

Checking activation

- Disconnect connectors from all six fuel injectors.
(afterward check DTC memory)

If specified values are not obtained: - Connect VAG1527B voltage tester as follows:Harness connector
Terminal
Measure to
3 Engine Ground (GND)
4 Engine Ground (GND)
5 Engine Ground (GND)
- Operate starter for a few seconds.

LED must blink (brief blink signal).
- Switch ignition off.
- Connect VAG1598/31 test box at wiring harness to ECM, do not
connect ECM Page 24
-17
.
Pa
ge 15 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

28-15
Component location Overview of Component
Locations, page Page 24
-5

Test sequence

- Connect VAS5051 tester or VAG1551 scan tool
and select the control module for engine
electronics using "address word" 01 Page 01
-
9 .

Ignition must remain switched on for this.Rapid data transfer
HELP
Select function XX

When indicated on display:
- Press buttons -0- and -8- to select "Read Measuring Value Block" and
press -Q- button to confirm input.
Read Measurin
g Value Block
Q
Input display group number XXX

When indicated on display:
- Press buttons -0-, -0- and -4- to select "display group number 004" and
press -Q- button to confirm input.
Read Measuring Value Block 4
1
2
3
4

Indicated on display:
- Check specified value for Intake Air Temperature (IAT) sensor in
display field 4:
Pa
ge 18 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

28-31

Test requirements:

Fuse for Engine Control Module (ECM) OK

Electrical Wiring Diagrams, Troubleshooting &
Component Locations binder

Battery voltage at least 12.7 V
Generator OK

Test sequence

- Connect VAG1598/31 test box at wiring harness
to ECM, do not connect ECM Page 24
-17
.

- Switch ignition on.

Note:

The plus voltage supply for the Engine Control
Module (ECM) travels via connector terminal 3
(terminal 15) and connector terminal 62
(terminal 30).
Ground (GND) supply of the Engine Control
Pa
ge 34 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

28-32

- Connect multimeter for voltage measurement as
follows:

VAG1598/31 test box
Socket
Measure to
1 B+
2 B+
62 Engine Ground (GND)


Specification: approx. battery voltage

- Connect multimeter for voltage measurement as
follows:

VAG1598/31 test box
Socket
Measure to
3 Engine Ground (GND)

- Switch ignition on.


Specification: approx. battery voltage
If specified values are not obtained:
Pa
ge 36 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

28-33

Knock recognition control stop,
checking

The following tests must be performed when a
DTC is stored that relates to "knock recognition
control limit reached".

Possible cause
Corrective action
DTC for all cylinders
Poor fuel quality- Change fuel quality
(see operating instructions)
or
DTC for all cylinders in one
row Knock sensor tightened to incorrect
torque - Loosen knock sensors and tighten to 20
Nm
Knock sensor faulty- Check knock sensors Page 28
-41

Corrosion at harness connector
Engine accessories loose- Secure engine accessories
DTC for one Cylinder Engine damage- Check compression pressure
Engine accessories loose- Secure engine accessories

- Also check ignition angle retardation of the
individual cylinders Page 28
-34
.
Pa
ge 38 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

28-34

Check ignition angle retardation of the
individual cylinders

- Connect VAS5051 tester or VAG1551 scan tool
and select the control module for engine
electronics using "address word" 01 Page 01
-
9 .

Engine must run at idle for this.Rapid data transfer
HELP
Select function XX

When indicated on display:
- Press buttons -0- and -8- to select "Read Measuring Value Block" and
press -Q- button to confirm input.
Read Measuring Value Block
Q
Input displa
y group number XXX

When indicated on display:
- Press buttons -0-, -2- and -0- to select "display group number 020" and
press -Q- button to confirm input.
Read Measuring Value Block 20
1
2
3
4

When indicated on display:
- Check indication in all display fields.
Pa
ge 39 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

28-35


Display fields

1 2 3 4
Display group 020: Ignition -knock control in driving operation
Display
xx.x KW
xx.x KW
xx.x KW
xx.x KW
Indicated
Ignition angle
retardation cylinder 1
via knock control
Knock sensor control Ignition angle
retardation cylinder 2
via knock control
Knock sensor control Ignition angle
retardation cylinder 3
via knock control
Knock sensor control Ignition angle
retardation cylinder 4
via knock control
Knock sensor control
Specified
value 0 to 12 KW
0 to 12 KW
0 to 12 KW
0 to 12 KW
Notes Evaluation Page 28
-40

Note:
The number values indicated in display fields 1 to 4 represent actual ignition angle retardation via knock control of the
individual cylinders. Ignition angle retardation occurs in KW (crankshaft degrees) toward retardation.
- Press -C- button.Read Measuring Value Block
Q
Input display group number XXX

When indicated on display:
- Press buttons -0-, -2- and -1- to select "display group number 021" and press -
Q- button to confirm input.
Read Measuring Value Block 21
1
2
3
4

When indicated on display:
- Check indication in display field 1 and 2.
Pa
ge 40 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

28-36


Display fields

1 2 3 4
Display group 021: Ignition -knock control in driving operation
Display
xx.x KW
xx.x KW


Indicated
Ignition angle retardation cylinder 5 via
knock control
Knock sensor control Ignition angle retardation cylinder 6 via
knock control
Knock sensor control

Specified
value 0 to 12 KW
0 to 12 KW


Notes Evaluation Page 28
-40



Note:
The number values indicated in display fields 1 and 2 represent actual ignition angle retardation via knock control of the
individual cylinders. Ignition angle retardation occurs in KW (crankshaft degrees) toward retardation.
- Press -C- button.Read Measurin
g Value Block
Q
Input displa
y group number XXX

When indicated on display:
- Press buttons -0-, -2- and -2- to select "display group number 022" and press -Q-
button to confirm input.
Read Measuring Value Block 22
1
2
3
4

When indicated on display:
- Check indications in display field 3 and 4.
Pa
ge 41 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

28-37


Display fields

1 2 3 4
Display group 022: 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 1
via knock control
Knock sensor control Ignition angle retardation cylinder 2
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
1 and 2. Ignition angle retardation occurs in KW (crankshaft degrees) toward retardation.
- Press -C- button.Read Measurin
g Value Block
Q
Input displa
y group number XXX

When indicated on display:
- Press buttons -0-, -2- and -3- to select "display group number 023" and press -Q-
button to confirm input.
Read Measuring Value Block 23
1
2
3
4

When indicated on display:
- Check indications in display field 3 and 4.
Pa
ge 42 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

28-38


Display fields

1 2 3 4
Display group 023: 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 3
via knock control
Knock sensor control Ignition angle retardation cylinder 4
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
3 and 4. Ignition angle retardation occurs in KW (crankshaft degrees) toward retardation.
- Press -C- button.Read Measurin
g Value Block
Q
Input displa
y group number XXX

When indicated on display:
- Press buttons -0-, -2- and -4- to select "display group number 024" and press -Q-
button to confirm input.
Read Measuring Value Block 24
1
2
3
4

When indicated on display:
- Check indications in display field 3 and 4.
Pa
ge 43 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