My 9ooo speedo stopped working and the car started cutting out at the same time.
are these problems related and what can I do to fix it

Keith,

The two problems are related. the Speedo has to work for the ECU (Brain)to work correctly.
It uses speedo readings to assess idle revs, when changing gear or stood still.

I thought it might be, is there anything I can do to fix

Keith

It likely to be the sensor at the end of the speedo cable may need replacing, or if is is intermitamnt fault it could be that the speedo cable has come loose at one of the either ends.

Check under the bonnet first as you may not have to go throught the hassle of dismantling half the dashboard to get to the back of your clocks!

I think you are up the wrong creek here. The speedo is electronic and takes its signal from a sensor mounted at the upper rear of the gearbox which is driven from the differentail crown wheel. Usual problem with sesnor is that the nylon gear teeth strip off.
The ECU does not use the speed sensor to make adjustments to the fueling.
The trip computer and cruise control do however.
If the car is cutting out at the same time as the speedo stops working it is more likely that there is a problem with a common electrical supply.

Without the speedo working the engine will stall due to the fact that there is no road speed signal and the fuel system cannot work out the idle. The speedo transducer is located on top of the gearbox/differential housing. There is an A/C voltage from the transducer which is converted to a digital signal on the back of the speedo head. We have experienced a couple of problems caused by the drive gear that spins the transducer failing in the gearbox.

Just some more Info on the subject Found @ Reading Saab's webpage

Ah, yes. Reading Saab - another one of my websites ;-)

The note in question that Oles refers to is at: http://www.readingsaab.com/service/answers_mar00.html

HTH
/john

Umm, are we talking Trionic or LH system here? Dont know much about about the Trionic system but I'm sure the LH only uses rpm signal from the crankshaft sensor for fueling and idle control not the speedo signal. So I'd go with Derek on this one.

I've not had my speedo working for a few weeks now, but I have had no problems with the car cutting out. As previuosly mentioned, The cruise control and computer don't work, but all other areas are fine. My problem is that I can't get hold of the right sender unit!!!!!