ECU / ECM DIED! Need help!

[Dubstep808]

So today I was driving and I went to slow down from 45mph to 25mph then all of a sudden my car shut off and all the lights on the dash came on, The power steering went out and I had manual breaks but luckily I had a spot to pull off the road and park. Once I parked I shifted back into part and tried to turn the car back on but I got nothing, the cars cluster would come on but the next click would turn it back off like starting the car was not an option. It literally does nothing when the break is pressed with your foot and you try to click the ignition it just goes into aux mode, when holding the break and in aux mode I can still change gears like park to neutral but it wont even attempt to start in any gear.

Long story short I plugged in a OBD2 Reader I had and I got a u0100 lost communication with ecm/pcm "a" that isnt able to be cleared, I then decided to check out the ecm under the hood by the break booster and noticed the clip wasn't fully secure and the ground right next to it was a bit rusty so I clipped the ecm/ecu connector back down and cleaned the ground but its still doing the same thing, I did notice the ecm/ecu has a bit of moister looking texture on it so i'm guessing it might be the issue. Now that being said I found a few used ones for sale on ebay but if I swapped one into my car would it still work? or would I need Hyundai to re flash it with the right vin so the immobilizer pairs up?

Other Info:

2009 Genesis sedan 4.6

Any help is greatly appreciated, Thanks in advance!

 

[asidrave]

I know this does not answer your question but have you tried to dry out the ECU\ECM? Maybe disassemble it to clean and dry it out. Just a thought.

 

[OUsig]

I had the same thing happen to me on the drive into work going 70mph on the highway. luckily I could coast to the side and have roof on the shoulder to wait. towed to the dealership and they replaced the passenger side fuse box. found a short in it
maybe will fix your problem?

 

[daviderle]

I would have tried to disconnect the battery for at least 15 minutes prior to plugging the ÉCU back... but that is just me..

 

[Dubstep808]

I had the same thing happen to me on the drive into work going 70mph on the highway. luckily I could coast to the side and have roof on the shoulder to wait. towed to the dealership and they replaced the passenger side fuse box. found a short in it
maybe will fix your problem?

Did the cluster still come on and seem to "crash" when you tried to start the car back up?

 

[OUsig]

Did the cluster still come on and seem to "crash" when you tried to start the car back up?

pretty much
the car simply died when cruise was set at 70mph. I tried to shift to neutral then restart but no go
I pulled over and it acted like a dead battery. then I waited a few minutes and got it to start but it was VERY rough so I knew something was up I was hoping to get off the highway.
it died about 10 seconds later then no go
the electronics worked but no engine
again replaced the passenger side fuse box in the engine bay. all good after that

 

[coolie569]

pretty much
the car simply died when cruise was set at 70mph. I tried to shift to neutral then restart but no go
I pulled over and it acted like a dead battery. then I waited a few minutes and got it to start but it was VERY rough so I knew something was up I was hoping to get off the highway.
it died about 10 seconds later then no go
the electronics worked but no engine
again replaced the passenger side fuse box in the engine bay. all good after that

Older thread but hopefully I can still get an answer. Did they replace a specific fuse in the passenger side or the whole fuse box? Same thing just happened to me tonight.

 

[Dubstep808]

Older thread but hopefully I can still get an answer. Did they replace a specific fuse in the passenger side or the whole fuse box? Same thing just happened to me tonight.

I bought a whole passenger side fuse box off ebay but it didn't change anything, I bought a GDS/VCI Scan tool off obd2tool.com after to try and scan the system but it wouldn't make the "Handshake" to auto id the vin so I knew it was either the wiring or the ecu. I tested the wiring for power and from the obd2 port with a multimeter but that tested "OK" so I opt out to spend the money on a new ECU from Hyundai Parts - Genuine OEM Hyundai Parts and Accessories Online and installed it, after it was installed I had to take it to the dealership where they programmed the new ECU to match the vin. NOTE: USED ECUs WILL NOT WORK! once they are installed they are forever paired to that car with that vin number. If you have any questions join our group on facebook where I can message back faster (2009 - 2014 Genesis owners & car enthusiasts)

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- Allen

 

[Jackson1]

I bought a whole passenger side fuse box off ebay but it didn't change anything, I bought a GDS/VCI Scan tool off obd2tool.com after to try and scan the system but it wouldn't make the "Handshake" to auto id the vin so I knew it was either the wiring or the ecu. I tested the wiring for power and from the obd2 port with a multimeter but that tested "OK" so I opt out to spend the money on a new ECU from Hyundai Parts - Genuine OEM Hyundai Parts and Accessories Online and installed it, after it was installed I had to take it to the dealership where they programmed the new ECU to match the vin. NOTE: USED ECUs WILL NOT WORK! once they are installed they are forever paired to that car with that vin number. If you have any questions join our group on facebook where I can message back faster (2009 - 2014 Genesis owners & car enthusiasts)

Facebook Groups

- Allen

Did the new ECM work? My car has been down for months now trying to find right used ECM, then finally getting it shipped, programmed and installed only to find out that it does not fix the problem. Hyundai is telling me a new one will take until February to receive and is non refundable. My fear is that even a new one may not fix the problem and I will be stuck with a very expensive part. My questions to you are: Did the new ECM fix the problem and are you sure that a used ECM won't work?

 

[Dubstep808]

Did the new ECM work? My car has been down for months now trying to find right used ECM, then finally getting it shipped, programmed and installed only to find out that it does not fix the problem. Hyundai is telling me a new one will take until February to receive and is non refundable. My fear is that even a new one may not fix the problem and I will be stuck with a very expensive part. My questions to you are: Did the new ECM fix the problem and are you sure that a used ECM won't work?

A used ecm/ecu will not work, its vin locked to the vehicle it was installed in and cannot be reprogammed. I ordered mine from Hyundaipartsdeal.com for $1200 then installed it and had it programmed at the dealership, a good way to tell if your ecu is bad is see if you have a check engine light when on acc or trying to start the car. Usually when you'd turn the car onto aux mode all the lights would flash including the check engine light, if its not on or didnt flash with the others its mostlikely a bad ecu

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[Dubstep808]

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[pchelka]

hmm So Immo will not allow it to start ?

That's a bummer I'm trying to swap 4.6 with ecu int GC body with 2.0 harness but if its vin locked then BCM and the immobilizer unit will give me problems.

 

[Malik]

Was it the ecu

 

[Gabriel]

A used ecm/ecu will not work, its vin locked to the vehicle it was installed in and cannot be reprogammed. I ordered mine from Hyundaipartsdeal.com for $1200 then installed it and had it programmed at the dealership, a good way to tell if your ecu is bad is see if you have a check engine light when on acc or trying to start the car. Usually when you'd turn the car onto aux mode all the lights would flash including the check engine light, if its not on or didnt flash with the others its mostlikely a bad ecu

How much did the dealer charge you to program the new ECU?

 

[Sammy901]

Update related to incorrect information. The above posters claiming you can't use a used ECM are incorrect. My 2014 Genesis Type R Sedan ECM fried itself at 110,000 miles. I did the research and you can use a used part, but it must be re-flashed at a Hyundai Dealer with your VIN and possibly some other info related to your particular car, not an aftermarket online business. I had some corrosion in the trunk from water intrusion so they had to weld a new grounding point for the negative terminal coming off the battery. Total charge for the work and reflash was $975 and I bought a used ECM for $150 from a local junkyard (think best price online was $1800 for a new one)--Note the ECM's are the same for the 2012-2014 Genesis Type R and other models, but the part number changes depending on the year. My ECM on my 2014 is from a 2012, but it's the same part. Guy at the junkyard looked all the info and gave me a copy so the dealer wouldn't give me any crap. Tipped him $20 because they saved me a lot of money. All work was done at Courtesy Hyundai in Tampa Florida.

 

[OUsig]

very nice
it pays to know what you are looking for! And a dealership that will play along.
If anyone cares…my Genesis is running great and I added a nice sub and amp to the trunk.

 

[Bam8311]

Update related to incorrect information. The above posters claiming you can't use a used ECM are incorrect. My 2014 Genesis Type R Sedan ECM fried itself at 110,000 miles. I did the research and you can use a used part, but it must be re-flashed at a Hyundai Dealer with your VIN and possibly some other info related to your particular car, not an aftermarket online business. I had some corrosion in the trunk from water intrusion so they had to weld a new grounding point for the negative terminal coming off the battery. Total charge for the work and reflash was $975 and I bought a used ECM for $150 from a local junkyard (think best price online was $1800 for a new one)--Note the ECM's are the same for the 2012-2014 Genesis Type R and other models, but the part number changes depending on the year. My ECM on my 2014 is from a 2012, but it's the same part. Guy at the junkyard looked all the info and gave me a copy so the dealer wouldn't give me any crap. Tipped him $20 because they saved me a lot of money. All work was done at Courtesy Hyundai in Tampa Florida.

So courtesy Honda did a used ECM ?as I work for Midas in Sarasota and I reached out to them gettal Hyundai and Hyundai of Venice and they have all said the same thing that it has to be a new ECU. gettalHyundai will not touch it even if it's a new ECU Venice Hyundai tried to program a used ECU and was unsuccessful for me and courtesy Honda said that they now need new ECU so if you have a specific person you talk to there I'd love to get their info and contact so I can talk to them to get a 3.8 Genesis backup and running that is a beautiful car 90,000 mi only issue is the ECU went out

 

[LtPanther]

I have the same problem. I own a 2012 Hyundai Genesis Sedan Rspec 5.0 and the ECM died, dealer tried to program a used ECU I purchased and failed,the ECM I purchased had the exact same part number as my original ECM and still failed to program, is there a specific procedure I need to ask them to do? I figured the dealer software in their scan tools would be able to re write the vin to the used ECM I had installed in the car.

 

[ecuteam]

Hello guys, here is the solution for your Genesis ECU Problem:

 

[Charlie1982]

Good to know someone is able to dissect these and work things out!