check engine AUDI A4 1996 B5 / 1.G APB Engine Ignition System Checking
[x] Cancel search | Manufacturer: AUDI, Model Year: 1996, Model line: A4, Model: AUDI A4 1996 B5 / 1.GPages: 64, PDF Size: 0.37 MB
Page 35 of 64
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Control module voltage supply,
checking
Test requirements:
Fuse for Engine Control Module (ECM) OK
Electrical Wiring Diagrams, Troubleshooting &
Component Locations
Battery voltage at least 11 V
Generator OK
- Connect test box VAG1598/31 to wiring harness
for engine control module. Do not connect to the
engine control module itself. Page 24
-20
.
- Switch ignition on.
Note:
The B+ voltage supply for the engine control
module comes via terminal 3 (terminal 15) and
terminal 62 (terminal 30).
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Page 36 of 64
The Ground (GND) connection for the engine
control module is via terminals 1 and 2.
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Page 38 of 64
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Knock sensor control limit, checking
If the malfunction message "Knock control
regulation reached" is recorded in the DTC
memory the following tests must be carried out.
See also measuring value blocks 20, 21, 22, 23
and 24 Page 28
-35
Possible cause of malfunction
Corrective action
Malfunction
message relating to all cylinders
Poor fuel quality- Change to higher quality fuel (see Owner's
Manual)
or
malfunction
message relating to all cylinders in
one bank Incorrect tightening torque on
knock sensor - Loosen knock sensor, then tighten to 20
Nm (15 ft lb)
Knock sensor faulty- Check knock sensor Page 28
-41
.
Corrosion on connector
Loose components on engine- Secure loose components
Malfunction
message relating to one cylinder Mechanical engine damage- Check compression pressure
Loose components on engine- Secure loose components
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Page 42 of 64
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Display Group 22 -Ignition- Knock control
Driving mode
Read measuring value block
22
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 2 0...12 KW
(crankshaft
angle)
Page 28
-40
Ignition timing retard via knock control:
cylinder 1
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 1
and 2. The ignition timing retard occurs via KW (crankshaft angle).
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Page 43 of 64
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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).
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Page 44 of 64
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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).
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Page 45 of 64
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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
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Page 46 of 64
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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
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Page 48 of 64
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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
.
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Page 49 of 64
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- Check wiring connection from relevant sensor connector to...
- ....Engine Control Module (ECM) for open circuit and/or short to B+ or
Ground (GND).
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