Saab 9000 - Page 161

158
Fault
diagnosis
Diagnostic trouble code P0327
Knock sensor
Symptom of fault
The car runs on basic boost pressure only, continu-
ous ignition retard.
Note
The Saab Trionic system does not have a conven-
tional. knock sensor. The signal comes from the
ignition discharge module.
Conditions
• Engine. running
• No knock signal for 1
O
seconds.
346
589
Diagnostic help
A knock signal reading can be obtained using an
ISAT scan tool.
- Select "READ FUNCTIONS".
- Select "KNOCK SENSOR".
The
ISAr scan
tool should show a reading of be-
tween
O
and 2.55 V, depending on the level of the
knock signal.
At idling speed the ISAT scan tool should show a
reading of 0.06-0.16 V.
If the throttle is opened suddenly, the ISAT scan tool
could show a reading of 0.06-2.55
V.
In the event of a
break
in the signal lead connected
to pin 44 of the control module, a reading of
0.06-0.08 V will normally be obtained whatever the
throttle opening.
Saab 9000