Code p0685, ECU/ECM relay location needed

2007 KIA OPTIMA
174,798 MILES
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AALIYAHMC
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I have the car listed above with a 2.7. where can I find the ECU/ECM relay? I’m aware there is 2 one under the hood the other in the dashboard behind the radio but where and what does it look like? I’ve seen your diagram but it doesn't really explain where to look on my car. I’ve literally took everything apart in my car and can’t find it on the inside.
Sep 11, 2021 at 6:11 PM
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SQM
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Hello,

Have you already checked the main relay under the hood (see picture below)?
I have also attached the basic diagnostics for the code P0685.

Please note that code can be also for having bad wiring for that circuit, corrosion or having a short.

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Please let me know what you got.
Thank you.
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Sep 11, 2021 at 8:13 PM
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AALIYAHMC
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I’ve tried everything diagnostics says it’s the relay underneath the dashboard but I’ve tore my whole car apart and still can’t find where the second relay inside the car is.
Sep 12, 2021 at 2:24 AM
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SQM
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For the PCM Alldata only shows that one relay under the hood. Can you tell me which manual states there is a second one?
Sep 12, 2021 at 7:04 PM
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AALIYAHMC
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I called Kia dealership and they say there are two. one behind the dashboard and one underneath the hood.
Sep 13, 2021 at 4:46 AM
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SQM
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Interestingly I do not see the one under the dash on Alldata.
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Sep 13, 2021 at 9:14 PM