Testing a used ECM

[Mikevan10]

During the course of my recent OBDII war (epic P0446 battle), I procured a used ECM for my 1997 Legacy (the ECM is a type AD050). Turns out, my problem was not with the ECM at all (at least so far that is what I think/hope). But, in the heat of the battle, I did buy the ECM f(for 40 bucks)from some out of (my) state salvage yard. They said that it came out of a car with a functional engine. They said they had pulled the ECM out of the car and put it on a shelf where it sat until I ordered the part.

 

My question is, is there any risk associated with temporarily installing this ECM in my car just to see if it works? I would like to do that since the place I bought it from did tell me (verbally, over the phone) that it is warranted for 30 days plus I would just like to know for my own information if I have a "good spare" on hand in case I need it in the future.

 

What do you think?

 

Thanks,

 

Mike V

[OB99W]

During the course of my recent OBDII war (epic P0446 battle), I procured a used ECM for my 1997 Legacy (the ECM is a type AD050).[...]

 

My question is, is there any risk associated with temporarily installing this ECM in my car just to see if it works? I would like to do that since the place I bought it from did tell me (verbally, over the phone) that it is warranted for 30 days plus I would just like to know for my own information if I have a "good spare" on hand in case I need it in the future.

There's always some risk when attaching used electrical/electronic parts; heck, even new parts can have problems. However, in most cases involving an ECU/ECM, the risk is damage to it from external factors, and not nearly as much so to external parts from problems with the ECU.

 

Of course, if you connect the used ECU, and anything seems grossly wrong, you shouldn't continue to run it. Minor irregularities in running are probably to be expected until the ECU "learns" your engine, etc.

[Cougar]

I agree with OB99W. Any problem with it would be damage to the ECU internally not to external parts. The replacement unit will most likely have no trouble. Hook it up and check it out to be sure.

[hankosolder2]

I can only see one potential problem. The ECM regulates the 12-14v battery voltage down to +5 volts for all the sensors. In the very unlikely event the regulator circuit has failed, the ECM could conceivably dump full battery voltage to every sensor. It's a longshot, but possible.

 

Nathan

 

During the course of my recent OBDII war (epic P0446 battle), I procured a used ECM for my 1997 Legacy (the ECM is a type AD050). Turns out, my problem was not with the ECM at all (at least so far that is what I think/hope). But, in the heat of the battle, I did buy the ECM f(for 40 bucks)from some out of (my) state salvage yard. They said that it came out of a car with a functional engine. They said they had pulled the ECM out of the car and put it on a shelf where it sat until I ordered the part.

 

My question is, is there any risk associated with temporarily installing this ECM in my car just to see if it works? I would like to do that since the place I bought it from did tell me (verbally, over the phone) that it is warranted for 30 days plus I would just like to know for my own information if I have a "good spare" on hand in case I need it in the future.

 

What do you think?

 

Thanks,

 

Mike V

[nipper]

I can only see one potential problem. The ECM regulates the 12-14v battery voltage down to +5 volts for all the sensors. In the very unlikely event the regulator circuit has failed, the ECM could conceivably dump full battery voltage to every sensor. It's a longshot, but possible.

 

Nathan

 

weird things happen, but usually its a ecu that blows up from a bad sensor (if anything is going to happen). Iv'e never heard of a ECU putting out too much voltage, i think they self desturct first if that happens.

 

nipper

[idosubaru]

i've swapped ECU's zillions of times without issue. did you know a 4 cylinder EA82 can run on a 6cylinder XT6 ECU????? not real well, but it does run.

 

in your case, don't sweat it.