# Immobilizer Active message after engine change



## alwaysdutch (Oct 19, 2011)

Is it normal that the message "Immobilizer Active" appears on the dash after an engine change? I have not started the engine yet as I need to add coolant and oil, but wondered if that is a normal sign after the battery has been removed for a long time.

just curious. Has anyone with an engine change seen this??


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## thygreyt (Jun 7, 2009)

this is where the fun begins


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## alwaysdutch (Oct 19, 2011)

Meaning??


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## pennsydubbin (Mar 3, 2010)

are you using your normal set of keys and not accidentally using the spare mechanic key or whatever it's called. I know this happened to me and I'm pretty sure it was because I lost my keys and was using one of the spares. I could be wrong on that though but I definitely had that problem happen to me.


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## alwaysdutch (Oct 19, 2011)

I only have one key as I lost a spare key long time ago. I was hoping it was due to the battery being removed for so long......I will have to see what happens this coming week when I am totally done with it.


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## TheZooKeeper (Jan 28, 2009)

No, it is not normal. The Immobilizer is an anti-theft device that ties your key, ECU, instrument cluster, and radio together. Are all of those items original? Did any of them get changed? If so, that would be the source of your problem. Having the battery unhooked for an extended period of time will not cause that to happen. Good luck!


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## alwaysdutch (Oct 19, 2011)

I changed out the ECM that came with the engine, but that is the only unit that changed. Would this be something that can be reprogrammed?


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## TheZooKeeper (Jan 28, 2009)

alwaysdutch said:


> I changed out the ECM that came with the engine, but that is the only unit that changed. Would this be something that can be reprogrammed?


That is the source of your issue. You will need to visit the dealership with the car and 2 keys so they can re-sync the the Immobilizer.


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## alwaysdutch (Oct 19, 2011)

I wonder if a Euro shop can do it. As long as the car cannot start, it will take me forever to get it to a dealership


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## thygreyt (Jun 7, 2009)

tow it


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## nothing-leaves-stock (Mar 1, 2005)

dealer only, sorry. had the same issue
tow it there


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## TheZooKeeper (Jan 28, 2009)

Dealership is your only choice.


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## alwaysdutch (Oct 19, 2011)

well damn...well, if that is the only issue I run into, I think I can handle that. Anyone know what the average charge is?


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## TheZooKeeper (Jan 28, 2009)

alwaysdutch said:


> well damn...well, if that is the only issue I run into, I think I can handle that. Anyone know what the average charge is?


$100 or so...depending on their hourly rate. Make sure you have a min. of 2 keys when you go for the appointment. They need to put one in the door and one in the ignition during the process...


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## alwaysdutch (Oct 19, 2011)

Well, make that 4350 then....I lost one of my fobs long time ago.......


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## TheZooKeeper (Jan 28, 2009)

alwaysdutch said:


> Well, make that 4350 then....I lost one of my fobs long time ago.......


I would just purchase a valet key at the dealership when you go. They're cheaper than the fobs...


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## alwaysdutch (Oct 19, 2011)

For those that are wondering, the engine will start when you keep the ECU from the old engine. I had the engine running today with the old ECU, while the newer ECU would need a sync.

I might do that once everything runs and I can actually test the car on the road. I am adding new cv axles and tie rods.


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## TheZooKeeper (Jan 28, 2009)

alwaysdutch said:


> For those that are wondering, the engine will start when you keep the ECU from the old engine. I had the engine running today with the old ECU, while the newer ECU would need a sync.
> 
> I might do that once everything runs and I can actually test the car on the road. I am adding new cv axles and tie rods.


No need to wonder on that. Of course it would still run. There is no need to swap ECU's if you're swapping the same motor in replace of what came out.


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## alwaysdutch (Oct 19, 2011)

Swapped '05 engine with a CBTA......


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## Jefnes3 (Aug 17, 2001)

alwaysdutch said:


> Swapped '05 engine with a CBTA......



Keep the original ECU.

There is no need for you to change boxes.



-Jeffrey Atwood


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## nothing-leaves-stock (Mar 1, 2005)

jeff, 
some states you have to "plug in" the car for emissions. in pa that will read the ecu number, VIN and other info. if that doesn't match, then theres a BIG issue. 
since you know more about ECU's then i, will this be a problem for this car to make it "legal" since it is a differnt year and all? i THINK in Pa it would.

by the way, merry chrstmas
-josh


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## pennsydubbin (Mar 3, 2010)

^ that is something I need to know for future inspections.


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## Jefnes3 (Aug 17, 2001)

Josh,

Simplest/best way: keep the original ecu. In this case (for a 2.5)
There is no reason to change it.
No immo defeat required.
No key matching required.

The vin in the original ecu will match the plate on chassis.


-Jeff


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## nothing-leaves-stock (Mar 1, 2005)

jeff,
correct. but if the motor is differnt then the year car. like jimmi's above, he had a 2005.5 and put a 2008 motor in, differnt motor, cams, ecu etc.....you can't run that motor on the 2005.5 ecu...so what then?


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## PhAyzoN (Nov 29, 2010)

Is there any reason 08 software (OEM or aftermarket) couldn't be flashed to an 05.5 ECU? I thought a lot of the aftermarket flashes changed the behavior of the 05-07 to be more like an 08 anyway.


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## alwaysdutch (Oct 19, 2011)

I am sure it could be done, but it would cost me whatever the dealership charges, plus in my case an additional key. Since the software is practically the same for the '08 as on the '05, I opted to keep the '05 ECU and save some money.

I am hoping to simply sell the '08 ECU again as it came with the '08 engine.


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## nothing-leaves-stock (Mar 1, 2005)

jeff could say better then me, but i'm 99% sure that is not possible because the motor is differnt as well


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