fuel pressure AUDI A8 1999 D2 / 1.G ATQ Engine Ignition System Checking Workshop Manual
Page 38 of 65
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
.
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Page 45 of 65
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
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Page 65 of 65
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:
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