Misfire, no power to coil bank number three cylinders number three and number six

HITECHMECH1

MEMBER
2003 HYUNDAI SANTA FE
2.7L
V6
2WD
AUTOMATIC
150 MILES

I’ve already gone through all the troubleshooting steps coil is in good working order plugs all good.

Did a Resistance test as follows on the four pin Molex plug going to the ECM.

GRN -> >
Wht. 4m ohm
blk. 4m ohm
y. 8k

I’m not sure if the driver circuit for “y” is it a default closed position or if this is indicating a problem, I have verified everything. I swapped the coils plugs and it’s definitely the driver circuit that is not firing the coil. My last attempt is to read the resistance directly at the ECM and depending on results run a separate wire from the ECM to that coil.
Any advice would be appreciated, and I was wondering if you could send me a picture of the plug C23-5 as it is difficult to see and navigate in that area. I’m assuming it is the nine-pin plug right next to the power plug. What has me a little confused is that it appears that the wire size at the ECM or a smaller gauge than what is in the engine compartment at the Molex plug going to the harness. I don’t want to start cutting wires if I don’t need to. I look forward to your response. Thank you

1 Reply

KASEKENNY

MECHANIC
18,907 POSTS

Can you help me understand a little more where you checked this resistance? You said you did this at the 4-pin connector at the coil correct?

So where were your meter leads? Each one of these pins and ground? So, you were checking resistance to ground through the coil?

Or were you checking the resistance back through the PCM to ground?

I assume you are checking this resistance back through the control circuits of the PCM and if you are then it sounds like we have an issue on the yellow circuit.

Also, I am not sure why you are thinking you need to run a separate wire from the PCM to the coil other than you suspect there is an open circuit on that wire?

If that is the case, then we need to check that by checking the resistance from connector to connector of the coil to the ECM.

You should have less than a half ohm. If you do, then the wire is intact. It may not be able to carry a load, but it is not an open circuit but if you have no power then that would be the concern.

https://www.2carpros.com/articles/how-to-check-for-ignition-spark

https://www.2carpros.com/articles/how-to-test-an-ignition-system

It sounds like you have an ECM failure but clearly that may be due to me not understanding the testing locations that you are using to get the results you are getting.

Let me know this info and we can go from there.

I attached the info below that you requested.

Thanks

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