ECM Servicing & Testing
 

OK ordered another new IACV, TPS, crank position sensors, and cam position sensor.

Because I didn't want to get another bad ECM, I searched around and tried to buy an OEM one, but they are totally out everywhere. I searched and found a single unit on ebay matching my A56-Q14-Z91 code.

My question, since when I inspected my ECM there was no visible damage and no smell, is there any way to actually test them? I have read in some searches occasionally some of the servicing companies hook them up to a known good IACV? I would like to avoid dropping any more money on this problem :)

Can anyone help? I ordered that ebay one. I am trying to understand the difference with part# vs firmware# for these. Am I correct that A56-Q14-Z91 represents the firmware of the ECM and that since it matches my existing ECM I won't need to get it reprogrammed at the stealership? I will only need to get the keys synced?

Your ECU knows the identity of the keys for your car. No other ECU has this knowledge; that's why when you replace your ECU, it has to be programmed to learn the identity of your keys.

So, having your ECU fixed is the easiest way to go. The document about ECU failures (link in my signature) has links to places that fix ECUs. If you decide to buy a "new" ECU, you have to ensure that: a) It's the correct ECU for your car/model, and b) That it's programmed to know about your keys.

So as long as the donor vehicle matches me on trans., year, and emissions spec. I am good? Those are the only 3 for sure details I know, and the fact that the A56-Q14-Z91 codes match.

I am aware of the key thing. Basically unless I hear otherwise since those things all match I am going to treat it as plug and play. Friday morning I am gonna do the IACV, TPS, as well as the crank and cam position sensors, install the donor ECM and at 2PM the locksmith is coming by to do the key programming.

That ECU write up is top quality work. You must be an engineer haha. I will of course be implementing bypass and fuse replacement. Got the IACV and sensors from Courtesy in TX.

Does the repair affect the status of programming? Specifically I have had my timing advanced, and the donor one has not. Even though I bought the donor I would still like to send out my original for repair if that setting will be preserved. I'm not sure if the stealership where I live now will be willing to do that for me, or if they still can on their new Consult system (something the guy complained to me about when I tried to have them relearn idle when I had done the IACV only).

I would think that any/all programming will be preserved. The shop replaces the damaged power transistor(s), but it does not touch the EPROM (that's where all the programmed info is). This is why after having your ECU repaired, you don't have to worry about re-programming your keys.

Yeah that is logical. Unfortunately got called in for work today so had to postpone a week.