Hello everyone, I hope and pray that I can get this problem figured out.

It all started about a month and a half ago. I decided to upgrade my Evo 9 to forged internals, AMS intake manifold, AEM EMS, AEM Meth injection (and some other things) so that I could run the car without worrying of breaking it, since I was already running 28psi with the stock block and a GT35R kit, and got a best time of 11.55 in the quarter mile.

So everything was put together by what I thought was a reputable shop in Caracas, Venezuela. I live about 400 miles from there. The car was tuned and it was all wonderful. It was driven to my town by the tuner so that if anything came up it could be solved. Two days after the car was delivered, as I was driving it, it died on me. There was no way it would start. I connected the laptop and it never synched so there was no spark. I unplugged the AEM EMS and there was this burnt smell from the inside. So seeing that it would take more than a month to send it back for repair, I decide to open it and I found this:






So as you can see, there was a burned track in the board. It went to the ECU pins that are supposed to be "sensor ground", per the stock ECU pinout.

As soon as the track was fixed, the car started right the first time I tried. But as soon as I drove it again, it happened again, but this time in other part of the board but still a "ground" track:



I fixed the second opened track and the car started right again. I thought that maybe the ground was deffective and I installed a wire from the ECU carcass to the car chassis. I left the ECU without the case to see if something was getting hot. I found that one of the power dirvers was getting REALLY hot. One of the pins of this driver was connected to the MIVEC signal pin. I disconnected the MIVEC solenoid connector in the engine bay and the overheating problem went away.

I thought that maybe the MIVEC solenoid was toasted, but as I tested it I found out its resistance value was within the acceptance range, 7 ohms.

I left the car parked for two or three weeks and started it every couple of days and let it idle for about 15 minutes each time. Well, yesterday I drove the car and guess what? It had to be towed again.

So I took the ECU apart again and found another ground track open and three overheated places. Here are the pics:

Opened track and overheated zone #1


This is where the overheating part belongs to at the other side of the board


Overheat #2


Reverse part of Overheat #2


Overheat #3


Reverse Overheat #3



At this point in time the shop guys seem to be clueless about this problem and don't seem to want to solve it either. So, maybe someone that knows how this ECU works could tell me why is this happening. I have tested every fricking cable at the ECU connectors and I could not find anyhing out of order. There was no cable shorted out or grounded that I could find, and I took a long time to test every wire with a lot of pacience.

If the ECU is defective I don't mind having to pay for another one (I know the warranty ended at the time I opened it), but I have to be sure about this since I don't want two of these expensive ECUs laying in my office doing paperweight job.

I have searched to see if someone else is having this problem and could not find anything else. Maybe an AEM guru can diagnose this problem by just looking at the places that the board is getting hot???

Sorry for the long post, but I really ran out of options here

 

when you did the engine work, did they reconnect all the ground wires in the engine bay? I would check the gound wire in the engine bay to make sure that the are properly mounted and secured. Seems you have a weak grounding and the engine sensors are searching for the ground signal thru the AEM.

I'm no guru, but it just seems like some thing you should check out.

Good luck

 

Send it out to AEM ask them to repair it. It will be cheaper then buying a new one. Ask them If they can help you track down the issue. I'm no electronic guru either. If the stock ecu runs fine I would venture to say who ever installed the ecu mess up something. I would also go over every wire in the engine bay and see if anything looks out of place. Find out what pins got burned out so we can help you track the issue. AEM might be able to tell you about it. Also if the ECU was used, it could of been damaged by the original owner.

 

That's what I thought at first time. But every ground wire was checked. Also, an HKS grounding system was installed prior to this problem and there are more ground wires in the engine bay right now than when the car was stock

 

I really took my time to check every wire in the 3 ECU connectors to check if there was a shorted wire. I did not find any grounded wire, except for those that must be grounded (chassis ground, etc). The tracks that are always burned all go to different ECU pins, but all of them are "sensor ground". One of the times that I started the car without the ECU carcass on it, I saw one of the power drivers getting really hot, and it was related to the MIVEC ECU pin.

And the AEM EMS was brand new

It seems odd that no one else has gotten this problem. My first guess is that it was external to the ECU, but as the time goes by, I guess it's ECU related. At this point I really don't know

 

It sounds like you have a bad ground somewhere and something drawing a large amount of power is taking the path of least resistance through your EMS.

 

If these things are heating up it most likely is the result of a short or "soft-short" on the board itself. That is assuming your source and signals into the box are clean. By that I mean there is no large source of current or device attached to it that is drawing far too much current. I would recommend you send it to AEM, they should be able to tell you what is killing it.
It does however sound from your description of the damaged traces, that it would be something you are connecting it to in the car. If I were you I would start looking with a Multimeter and measuring current going out of you AEM to the car, sensors, etc.

 

That's what I'm thinking. I hope that's the problem

And I'm gonna take your advise in cheking the current going out to the sensors.

 

Did you have the car running on the stock ecu before you switch over??

 

Couldn't you email aem with this link....It is very specific and written well with pictures. It would be interesting to see if they could provide insight like your asking the forum to do.
Good luck btw.

 

It sounds like the installer may be using ecu "sensor ground" as grounds for other things such as gauges/EBC/whatever he wanted. Sensor ground is ONLY for sensors and I think 5v sensors at that (double check me on that). If he is grounding 12v devices to "sensor" ground that may be a no no on your ecu. You can check the sensor ground for the stock ECU in the FSM.

12v devices like the engine bay solenoids are grounded to chassis ground typically.

 

Yup. I would start looking external to the ECU, for anything that could be using sensor ground to sink large amounts of current.

The reason your traces are burning up, is because they're effectively turning into fuses. Every time you add a wire to fix a burned trace, you're increasing the current capacity of that part of the circuit, which will cause the next weakest link to burn up.

 

hrm...i would get frustrated and buy another AEM EMS, HKS v-con pro? but if your car is shorting the ECU, its risky

 

Yes. It was great though. I'm thinking on switching back to the stock ECU

 

I opened a new thread at the AEM forums before this one. Too bad nobody has said anything yet. Here is the link:

http://forum.aempower.com/forum/inde...c,23931.0.html