Saab 9000 - Page 226

Poor performance
1
Diagnostic procedure
General fault diagnosis procedure for poor perfor-
mance is difficult to concretize. However, some ad-
vice which may be helpful is given in the following.
1
Check pressure sensor operation
- Tum the ignition switch to the ON position and
then back to the OFF position.
- Select
"READ
FUNCTIONS".
-
Select
"INTAKE
PRESSURE".
The ISAT scan tool should show a reading of about
102 kPa (NOTE: the reading is dependent on air
pressure).
- First build up a positive pressure of 0.6 bar and
then create a negative pressure of - 0.6 bar.
Use a presure gauge and pressure/vacuum
pump.
The ISAT scan tool should show readings of 160
±
5 kPa and 40
±
5 kPa respectively (the ISAT scan
tool readings may be somewhat lower at high alti-
tudes).
Fault diagnosis 223
0000
0000
0000
0000
00(=:J
102 kPa
+0.6
bar
[~~
0000
0000
0000
0000
0 0
c::J
0000
0000
DODO
0000
0 0
c::J
-0.6
bar
40±0.5
kPa
Are the ISAT scan tool readings correct?
I
YES
I
The pressure sensor is OK.
I
NO
I
Change the pressure sensor.
Note
Boost pressure on cars with a manual gearbox is
limited in 1st gear.
Saab9000
I