Engine Management Light

[mikejgeo]

Odd one..

2002 9-5 Aero

Noticed engine management light was on.... AND the temp gauge showed cold [after 20 mins running]
Switched off, fluids all ok.
Started it and temp showed normal, after a few minutes gauge went to zero.
Removed ECU fuse, light went out, after a few mins running it came back on [and temp showed zero]
Car appears to run fine, cruise control working as normal.

TIA,

Mike

[mikeloadsasaabs]

All you can do is get it hooked up to a code reader, anything else is a stab in the dark! When you get the code, it may be obscure, so re-post if you need help interpreting it. I would guess at a faulty water temperature sensor but impossible to say really.

[sgould]

If the temp shows zero when the car is ticking over and stationary, it's likely to be the sensor.   If it reads OK when ticking over and not moving, but drop when on the open road, it's likely to be the thermostat stuck open.

But it could be other things.  Getting the codes read and doing a correct diagnosis and fix is likely to be cheaper than guessing and changing parts.

[Audax]

I'd suggest one of 2 things, either get the codes read and use that for proper diagnosis, or replace the coolant temp sensor and the thermostat, if you've no record of the coolant temp sensor and thermostat being done then it might be worthwhile just doing them anyway as they are not expensive but if you do this make sure you get genuine Saab parts, they're worth the small premium over non-genuine for this stuff as the non-genuine bits can cause new problems due to many of them being of dubious quality.

[mikejgeo]

Thanks all,

Will the codes be affected by pulling  fuse 17?

Mike

[sgould]

Yes, it will clear the codes and any record of them.  But if there's a fault, and it's still there, the code will be stored again.