Fault diagnosis 207
Diagnostic trouble code
Pt549
(contd.)
5~
5 Check the power supply
- Ignition switch in ON position.
- Check that the valve is supplied with power
(+54
circuit) by connecting a test lamp to pin
2
of the valve's connector and a good grounding
point.
Is the test lamp on?
I
YES
I
Continue with point 6.
I
NO
I
Repair or replace the lead between pin 2 of
the connector and fuse 5. Then continue
with point 9.
6
6 Check the resistance of the valve
- Take resistance readings in the valve's connec-
tor across:
• Pins 1 and 2
• Pins
2 and 3
Nominal resistance is 3
±
1 ohm in both cases.
Are the readings OK?
I
YES
I
Continue with point 7.
INO
I Change the boost pressure control valve
and continue with point 9.
Important
If there is
a.
short circuit in any winding the control
module will probably also be damaged. If a new
valve is then fitted it will inevitably be rendered un-
serviceable. In the event of a short circuit, both
valve and control module must therefore be
changed at the same time.
If necessary, change fuse 5 afterwards.
Saab9000
I
To Next Page
Loading...
