Hi guys,

This is on a 2005 ML350 that we just purchased.
I am struggling to figure out how to find what part is faulty without just throwing parts at it as I know the system has a couple components.

I cleared the code, and it came back immediately on the 2nd start.

Anybody here dealt with this code before and can point me in the right direction to find exactly what is causing the CEL? I've spent hours on google now and I cannot find any definitive tests to help guide me on where to start.

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2016 Monsoon Gray Audi Allroad - 21k
2008 Black Mercedes E350 4Matic Sport - 131k
2014 Jeep Wranger Unlimited Sahara - 62k
2003 Gray Mercedes ML350 - 122k