Saab 9000 - Diagnostic Trouble Codes P0301, P0302, P0303, P0304

148 Fault diagnos·is
Diagnostic trouble codes ·P0301, P0302, P0303, P0304
Misfiring in cylinder 1, 2, 3 or 4
Symptom offault
The CHECK ENGINE lamp (MIL) is on or flashing.
Uneven running when misfiring.
Possibly other diagnostic trouble codes.
Conditions
An engine load and speed dependent matrix in the
electronic control module's memory specifies how
large a proportion of misfires is required for exhaust
emissions to reach prohibited limits or for the three
way catalytic converter to be damaged. If the number
of misfires exceeds the matrix value, a diagnostic
trouble code will be generated.
If misfiring occurs in more than one cylinder, the cyl-
inder in question accounts for more than 95% of the
misfires.
µp
µp
µp
µp
µp
µp
µp
µp
12 10 6 4
11 9 5 3
Diagnostic help
The injectors and the corresponding ignition coils
can be activated using an ISAT scan tool.
- Select "ACTIVATE".
. - Select "INJECTORS" and
"IGNITION COl°LS".
Then select the cylinder concerned in the appropri-
ate submenu.
Momentary misfiring can be ascertained using an
ISAT scan tool.
- Select "READ ·FUNCTIONS".
- Select "MISFIRING CYLINDER 1".
Other cylinders can also be selected.
Saab 9000