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P2453: Powertrain - Auxiliary Emission Controls - ISO/SAE Controlled, Diesel Particulate Filter Pressure Sensor "A" Circuit Range/Performance
P2585: Fuel Additive Control Module Warning Lamp Request.
Possible causes of OBD code P2585
No fuel additive in fuel additive tank
Fuel additive system malfunction
Fuel additive level sensor malfunction
Fuel additive control module malfunction
P1412: Secondary air system fault bank
1Drive cycle D:Signal implausible
P204F: Charge Air Cooler Bypass Position Sensor "A" Circuit High
P404: Exhaust Gas Recirculation Circuit Range/Performance
U1900: Can Communication Bus Fault
How to interpret all of that? Beyond me. From a really real amateur view point on modern diesel technology, you might have a shorted sensor or module. Something is dragging down your communication bus and, based on my experience with other computer controls, the problem more than like resides in a module on the com link rather than a sensor or controlling device. Try disconnecting the Fuel Additive Control Module, since that's one of the critters rearing it's ugly head. If it is a module, the faulty device might not actually be in the codes, though. If anyone else knows more about this, please speak up.