yeah i have another ECU to throw in and check. Any idea what could be causing the ECU to get so hot? Could it be getting hot because of a problem with the actual ecu or could it be the wiring?

 

Hi, I'd guess that if the ecu is hooped, or merely hot, it is for a reason, probably one external to the ECU.

um, MULTIPLEX MULTIPLEX MULTIPLEX!

They are famous for causing trouble as the solder ages.

resolder at will

 

I assume the ECU normally heats up in use, so I don't have a way to know whether your ECU is getting abnormally hot.

 

Can you explain how a faulty MCU would prevent a scan tool from communicating with the ECU?

 

Ok good news kinda... ECU was the problem i put the new one in and DLC connector works. Weird note was that a CEL was on the dash but after 20 or so seconds it flashed a few time and disappeared and code reader read no codes.
I guess you were right Civicalized about the twelve hour statement.

Thank you all for you input, knowledge, resources, and help.

Now that i know what failed does have any idea what could have caused this to occur?
Im hopping that if it does happen again its within my 100 day warranty on the ecu.

Also is their anyway to bypass the immobilizer? cause my keys do not match the ecu obviously so the car only cranks but does not turn over. Would driving the car with the bad ecu cause any damage? i really would like to get out of paying a tow truck or having a buddy tow me if at all possible.

once again thank you all for help

 

Excessive voltage from the alternator is about the only thing that can be wrong with the car that will burn out an ECU. Check all the grounds under the hood too.

I think you said for whatever reason (hopefully the ECU but can't be sure) your car won't go over 5 mph when using the old ECU so it doesn't seem practical to drive it anywhere like that.

 

well the voltage of the alternator was at 14.3 so that definitely didnt kill the ecu, it must have been a bad computer to begin with and the battery light must have been the warning sign of the ecu getting ready to go.

also the car wouldnt go over 5mph in first but would accelerate past that in d2 and d3

 

No, not really, but I was thinking that if the ecu is doing weird stuff, and it is connected to the MCU, then possibly bad connections in the MCU could be causing weird symptoms. Can an open connection in the MCU allow current to flow in unintended paths, probably, can that take out the ECU, probably not, but maybe. Floating grounds and higher voltages than intended could result. Sure that's a stretch, but I thought it was possibly worth checking before exposing a second ECU to a potentially harmful system.

I agree the ECU probably does run warm, but not hot.

Of course the question remains, what killed ECU #1 and how long will ECU #2 last? I simply distrust honda circuit boards, when I see weird symptoms I look at the relevant board first, more often than not that's where the problem is. Then again a 2003 vehicle does seem a tad young to have solder issues. Hopefully Glenn22 has the problem solved, time will tell.

 

BTW, with the new ECU is the batt light issue resolved?

 

the battery light problem is resolved so far i guess ill find out for sure once the car is started and running.