On-Board Diagnostics, or OBD, in an automotive context, is a generic term referring to a vehicle's self-diagnostic and reporting capability. OBD systems give the vehicle owner or a repair technician access to state of health information for various vehicle sub-systems. The amount of diagnostic information available via OBD has varied widely since the introduction in the early 1980s of on-board vehicle computers, which made OBD possible. Early instances of OBD would simply illuminate a malfunction indicator light, or MIL, if a problem were detected—but would not provide any information as to the nature of the problem. Modern OBD implementations use a standardised fast digital communications port to provide myriad real time data in addition to a standardised series of diagnostic trouble codes, or DTCs, which allow one to rapidly identify and remedy malfunctions within the vehicle.
1970: The United States Congress passes the Clean Air Act and establishes the Environmental Protection Agency.
~1980: On-board computers begin appearing on consumer vehicles, largely motivated by their need for real-time tuning of fuel injection systems. Simple OBD implementations appear, though there is no standardisation in what is monitored or how it is reported.
1982: General Motors implements an internal standard for its OBD called the Assembly Line Communications Link (ALCL), later renamed the Assembly Line Diagnostics Link (ALDL). The initial ALCL protocol communicates at 160 baud with Pulse-width modulation (PWM) signaling and monitors very few vehicle systems.
1986: An upgraded version of the ALDL protocol appears which communicates at 8192 baud with half-duplex UART signaling. This protocol is defined in GM XDE-5024B.
~1987: The California Air Resources Board (CARB) requires that all new vehicles sold in California starting in manufacturer's year 1988 (MY1988) have some basic OBD capability. The requirements they specify are generally referred to as the "OBD-I" standard, though this name is not applied until the introduction of OBD-II. The data link connector and its position are not standardised, nor is the data protocol.
1988: The Society of Automotive Engineers (SAE) recommends a standardised diagnostic connector and set of diagnostic test signals.
~1994: Motivated by a desire for a state-wide emissions testing program, the CARB issues the OBD-II specification and mandates that it be adopted for all cars sold in California starting in model year 1996 (see CCR Title 13 Section 1968.1 and 40 CFR Part 86 Section 86.094). The DTCs and connector suggested by the SAE are incorporated into this specification.
1996: The OBD-II specification is made mandatory for all cars sold in the United States.
2001: The European Union makes EOBD , a variant of OBD-II, mandatory for all petrol vehicles sold in the European Union, starting in MY2001 (see European emission standards Directive 98/69/EC  ).
2008: All cars sold in the United States are required to use the ISO 15765-4  signaling standard (a variant of the Controller Area Network (CAN) bus).
So your SAAB just does not seem to perform the way it once did?
Or you may have the 'CHECK ENGINE' light flashing at you when you turn the key?
These are the flash codes for trionic 5 ECUs
2 Flashes - MAP sensor
3 flashes - Intake air temperature sensor
4 flashes - Coolant temperature sensor
5 flashes - Throttle position sensor
6 flashes - Oxygen sensor (lambda probe)
7 flashes - Fuel / air mixture
8 flashes - EVAP valve
9 flashes - faulty ecu
"Check engine" fault codes More CEL codes here
How to check if the 'Check Engine' light comes on and stays on while driving:-
Pull over to the side of the road, turn the engine off, then turn the key to the on position.
The 'Check Engine' light will come on and start flashing, with a second in between each flash.
COUNT the FLASHES, this will give you a number which you can check with the above. This will indicate a fault which will give you an idea on what is wrong.
Hope this is of help to thoese that read, Please visit my shop.
A1 Andy's store,
Thanks again for your time