[kiamaian]

I will be driving my 1994 Saab CS on a 1000 km trip in a couple of days. However, today I was looking between the motor and the firewall to check the gearbox linkage joint when I saw a sensor hanging in mid air.

I can't find where the sensor should be placed. The shape and size of the sensor is exactly the same as the one which is installed into the lower half of the engine block underneath the exhaust manifold. The mounting bracket is the same too and wiring is enclosed in a black sleeve.

The car has been running for at least the past month without the sensor being mounted properly and I don't know what it's function is.

I would be pleased to be advised where the sensor mounts and what it is supposed to do.

 

[Derek]

Without a picture it is hard to imagine what you are seeing but the car won't run at all without the crankshaft position sensor (that's the one below the exhaust manifold).
The wiring looms have many extra connectors for parts which are options, or for other model variants, and these connectors may have a blanking plug in them - but not usually a mounting bracket. Any chance of posting a picture?

 

[kiamaian]

Sorry I can't provide a picture. However, the sensor is exactly the same as the crankshaft position sensor with the same shape mounting bracket and wiring contained in a black sleeve. (The wires are black and yellow)

I am wondering whether I have two crankshaft position sensors? The wiring is difficult to trace after it goes behind the motor.

 

[ms08]

You wouldn't have two crankshaft position sensors - is it possible that it has been changed at some time and the old one left hanging in the loom if they couldn't be bothered to untangle it - as Derek says - difficult to say fro sure without a picture.

Mike

 

[Derek]

As Locosaab says an old one may just have been left in place and as long as the car is running well it is probably nothing to be concerned about. But for peace of mind I really think you have no option but to trace the wire and see what it connects to if anything.

 

[kiamaian]

I agree that unless there is another sensor that looks exactly like the crankshaft position sensor in every regard that I am looking at a replaced sensor that has not been removed. I will follow your suggestion and trace the wiring back.

Thanks for all your responses.