Hello, The ecu on my car has packed in again. so was wondering if i brought another ecu from same sort off car will it work? or does it need to be recoded to the car

it needs to reprogram from dealer of the new ECM or ECU,should be good after that

try this it may work as i dont know your area, as im in uk but remove the air temp sensor on the filter box and see if that works, if it does it could just need replacing or you need a remap to the ecu as its reading the wrong signal. could even be a bad connection to the ecu so might just need a good clean on the ecu connector.

I would suggest you ask a local mechanic to have a look as i suspect a faulty computer but i have no pratical experiance with this american car ,now with my head under the bonnet i could no doubt have some idea but iam at a loss here as this is obviously a GM product which is a opel here in europe and iam wondering if this has the same siemans ECU as our cars and if it does then these age vehicles always have problems with this ECU ,its starts like you said with all the dials going right over then eventually it starts missing and throwing up all sorts of codes and the cause could be a simple as a coil pack shorting out but it damages the ECU big time but i could be totally wrong here and its completely different which is why i would advise you to ask a local man who works on these cars .

I would be leary about just replacing the ecu.especially if you can disconnect it and ir runs fine. Did they tell you what error messages there were? This would be helpful to know

you cannot get this sort of information its like proverbal rocking horse brown stuff ,dont want people like me doing repairs that the dealer wants ------- what sort of amperage are you drawing ,as i suspect either a low reserve amperage battery in your terms its sulphated up and need renewing or the alternator diode pack has a diode breaking down .Trust me you test a battery with a voltmeter ,only test for a battery is a drop tester ,your car will draw power when not used ,anything from clock to alarm and radio memory ,so check the battery with a drop tester as i think this is your problem

i've had similar issues with a 1999 M3. normally attributed to electrical power levels this could be a low voltage issue.

do you have error codes?

make sure the power contact at the starter motor (between the alternator and the battery) is tightened.

I have also had issues with a cranshaft position sensor. but my favourite culprit of electrical issues is a wet ECU.

the ecu compartment is under the windshield on the passenger side on E36

you gain acess to it under the hood....
this compartment gets wet, the ecu lays on a flat surface in that
compartment.

the bottom side of the circuit board gets wet and starts corrosion.

remove the ecu, take the bottom plate off, clean the bottom of the circuit
board with alcohol and a soft tooth brush.

you should be able to see the signs of corrosion or conductive build up.

this gunk bridges solder points doing all sort s of wierd things to your
car, including false sensor readings from asc/abs controllers and other
sensors....

all the way to engine failure and worst case burnt and shorted wiring
harness.

I'm on my 3rd ecu, took me and the repair boys a few years to figure this
one out.

BTW: i would get that ecu mounted above that flat surface, use some sort
of standoff to raise it so that it is not laying in the wet.

low power, bmw ecu has some code that starts shutting down systems on low power. so poor charging from the alternator to the battery.

this could also be a wet ecu tracking false codes.
i don't have direct experience with a series 5 but also check your ecu condition.

the ecu compartment is under the windshield on the passenger side on E36

you gain acess to it under the hood....
this compartment gets wet, the ecu lays on a flat surface in that
compartment.

the bottom side of the circuit board gets wet and starts corrosion.

remove the ecu, take the bottom plate off, clean the bottom of the circuit
board with alcohol and a soft tooth brush.

you should be able to see the signs of corrosion or conductive build up.

this gunk bridges solder points doing all sort s of wierd things to your
car, including false sensor readings from asc/abs controllers and other
sensors....

all the way to engine failure and worst case burnt and shorted wiring
harness.

I'm on my 3rd ecu, took me and the repair boys a few years to figure this
one out.

BTW: i would get that ecu mounted above that flat surface, use some sort
of standoff to raise it so that it is not laying in the wet.

wet ecu....

read the note below about E36

the ecu compartment is under the windshield on the passenger side on E36

you gain acess to it under the hood....
this compartment gets wet, the ecu lays on a flat surface in that
compartment.

the bottom side of the circuit board gets wet and starts corrosion.

remove the ecu, take the bottom plate off, clean the bottom of the circuit
board with alcohol and a soft tooth brush.

you should be able to see the signs of corrosion or conductive build up.

this gunk bridges solder points doing all sort s of wierd things to your
car, including false sensor readings from asc/abs controllers and other
sensors....

all the way to engine failure and worst case burnt and shorted wiring
harness.

I'm on my 3rd ecu, took me and the repair boys a few years to figure this
one out.

BTW: i would get that ecu mounted above that flat surface, use some sort
of standoff to raise it so that it is not laying in the wet.

PS...ignore person who answered...he is an intruder, and not part of the "team" !!!

problem is in the ignition module.