OBD port SAAB 9-3 2004 Owners Manual

194 Car careSaab Trionic engine management
systemThe Saab Trionic engine management
system is a unique Saab development that
combines sequential multiport fuel injection,
electronic distributorless ignition and turbo-
charger boost pressure control into one sys-
tem.
The Trionic engine control module (ECM)
monitors many different engine parameters
such as:
 Intake manifold pressure.
 Intake air temperature.
 Crankshaft position.
 Engine coolant temperature.
 Throttle position.
 The oxygen content of the exhaust gases.
The ECM receives information regarding
engine knocking from a sophisticated feed-
back function in the ignition discharge unit.
By processing all of this information, the Tri-
onic system can control fuel injector open-
ing duration, ignition timing and turbo-
charger boost pressure to provide excellent
engine performance while maintaining low
emissions and fuel consumption.
ORVR (Onboard Refueling Vapor
Recovery)All hydrocarbons formed when refueling will
be recovered by the car and not released
into the atmosphere. The hydrocarbons are
absorbed in an evaporative emission canis-
ter. When the engine is subsequently
started, the evaporative emission canister is
gradually purged as air is sucked into it
through a shut-off valve. The hydrocarbon/
air mixture passes through the evap canis-
ter purge valve and into the engine where it
is burned. “Refueling”, see page 147.
When refueling, make sure you screw the
filler cap on and keep turning until it has
clicked 3 times.
NOTICEThe Trionic engine management system
continuously monitors the operation of
these systems and has on-board diag-
nostic capabilities (OBD II). If the Engine
malfunction (CHECK ENGINE) light in
the main instrument illuminates, the
Trionic ECM has detected a problem. The
car will continue to operate, but perfor-
mance may be diminished. You should
have your car checked by a Saab dealer
as soon as possible.
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