Saab 9000 - Page 56

Boost pressure control (contd.)
2 26
If knocking occurs, despite retarding the ignition and
making the fuel/air mixture richer, the boost pressure
is also reduced.
If there is a break in any of the leads to the solenoid
valve, basic boost pressure will be obtained.
In the event of a break in any of the hoses or a fault
in the solenoid valve, excessively high boost pressu-
re may be obtained. The control module will then shut
off fuel injection at about 0.65-1.35 bar, depending
on the engine version.
Cars with automatic transmissi_on
When the selector lever is moved to a position other
than P or N, battery positive voltage (B+) will be appli-
ed to pin 14 of the control module, which will be pro-
grammed for automatic transmission. Cars with au-
tomatic transmission have reduced boost pressure.
Brake light switch
When the brake pedal is depressed, current (B+) is
supplied to the electronic control module on pin 15
and maximal boost pressure will then be the basic
boost pressure.
Technical Description 53
3 5
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2 4 R
µp
µp
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231
22A
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Reverse
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Basic boost pressure will be obtained when reverse
gear is engaged. This will take place when battery
positive voltage (B+) from the selector lever or rever-
sing light switch is applied to pin 13 of
the
control
mo-
dule.
Cruise Control
When Cruise Control is activated, pin 36 of the ECM
is grounded, making a reduction in boost pressure
possible. This does not take place in the Trionic sys-
tem on the M96 Saab 9000.
Speed limitation
Vehicle speed on cars equipped with a boost pressu-
re control valve is limited to 149 mph (240 km/h)
through boost pressure reduction.
Saab9000
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