| danielps69 |
My Murano recently failed to start, i checked out and all 6 coils were burned!!! Plastic just next to the electrical connector is burned... Installed a new coil (just one), ignition switch on, touch the new coil, it's hotter than hell! I replace ECM and coils, and now everything's ok.... After a few days, same thing! Brand new OEM ignition coils and ECM.
Any help will be highly appreciated. :confused: :3: |
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| njjoe |
danielps69-
Welcome to the forum.
According to the service manual, the supply voltage to the coils is the battery voltage, so it is impossible to send too much voltage to the coils.
You can check the voltage by disconnecting the connector and using a voltmeter from terminal #3 (see diagram below) to ground. The ignition must be on. The voltage should read the same as the battery voltage.
You obviously know what you are doing, but could it possibly be an over-voltage condition caused by a faulty alternator?
-njjoe |
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| Gonzo |
| I would think that if the voltage regulator (in the alternator) was bad there would other issues with the electrical system too. |
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| Eric L. |
| There is likely a short somewhere in the circuit - I would doublecheck all the various ground connections in the engine bay (yeah I know there are a ton of them) - the one that affects the coils is likely grounding right on the engine block. I don't know where this would be on the Murano but on my Maxima it is right beneath the intake plenum. |
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| njjoe |
quote:
Originally posted by Eric L.
There is likely a short somewhere in the circuit -
E-
When you think about it, I don't think there is a short in the coil circuit. If the short was upstream of the coils they would not be energized, and therefor would not be hot. If the short was downstream of the coils it would have no effect since the current goes to ground after the coils.
Something just does not sound right.
The ECM triggers the coils. Did it fail because the coils failed, or is it the other way around?
The coils list for $86 and the ECM for $821. That is over $1,300 in parts.
-njjoe |
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| Eric L. |
If the plastic around the coil connectors are warped, its pulling too much current, which is why I suggested a short somewhere. For it to affect the coil circuit, it has to be connected to it somehow, even if indirectly through the ECU (it should blow the ECU fuse though if this were the case). If the coil circuit is fed off the battery, which is think is a higher amp fuse, it could explain why so much current could get to the coils to begin with.
But then I am just guessing on this, since diagnosing via internet tends to be speculation at best.
quote:
Originally posted by njjoe
E-
When you think about it, I don't think there is a short in the coil circuit. If the short was upstream of the coils they would not be energized, and therefor would not be hot. If the short was downstream of the coils it would have no effect since the current goes to ground after the coils.
Something just does not sound right.
The ECM triggers the coils. Did it fail because the coils failed, or is it the other way around?
The coils list for $86 and the ECM for $821. That is over $1,300 in parts.
-njjoe
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| danielps69 |
| THANKS FOR THE HELP! Tell me about it! all the parts were way more than $1000... I was considering the idea of a bad alternator since they're recalled, but i just discard it 'cause my alternator was working ok and that can't explain why coils get hot even whit key on engine off. It looks like something blows ECM and the ECM then blows coils (old ECM blows new coils), this is my personal vehicle, thanks god i own a garage and a CONSULT-II so i didn't have to pay the stealer for the NATS initialization and VIN registraion.... STILL LOST!!! :confused: has somebody had a problem like this before?¿?¿ |
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| njjoe |
danielps69-
Electronics is not my forte, but could a failed condenser be the cause of the problems?
-njjoe |
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| Byron |
quote:
Originally posted by danielps69
THANKS FOR THE HELP! Tell me about it! all the parts were way more than $1000... I was considering the idea of a bad alternator since they're recalled, but i just discard it 'cause my alternator was working ok and that can't explain why coils get hot even whit key on engine off. It looks like something blows ECM and the ECM then blows coils (old ECM blows new coils), this is my personal vehicle, thanks god i own a garage and a CONSULT-II so i didn't have to pay the stealer for the NATS initialization and VIN registraion.... STILL LOST!!! :confused: has somebody had a problem like this before?¿?¿
Sorry to hear about such problems. The best I can tell, the ECM relay should cut the battery voltage with the switch off. Even with a constant ignition signal from the ECU, there should be no current with the switch off.
First, I would suggest checking to make sure the ECM relay is opening with the switch off. I don't think that is the problem, but I may be a part of it. After that, the only thing I can suggest is slowly and methodically checking the related circuits. I would start by confirming ground connections. Wish I could be of more assistance, but I can't come up with anything simple that would provide the constant signal from the ECU to the coils that would allow full current. |
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