Theory Of Operation

WARNING: This page is about a different car, the 2014 RAM 3500 HD and 2014 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

The Aftertreatment Diesel Oxidation Catalyst is designed to react with hydrocarbons in the exhaust stream, this chemical reaction reduces hydrocarbon emission levels and also produces heat. Periodically, the Powertrain Control Module (PCM) will utilize the heat generated by this reaction in the Aftertreatment Diesel Oxidation Catalyst (DOC) to actively regenerate and clean the Aftertreatment Diesel Particulate Filter (DPF). This diagnostic checks to ensure that the Aftertreatment DOC is present and functioning correctly. The PCM monitors the efficiency of the Aftertreatment DOC through interpretation of data received from the Aftertreatment DOC inlet Exhaust Temperature Sensor (1), the Aftertreatment DOC outlet Exhaust Temperature Sensor (2), and the Aftertreatment DPF outlet Exhaust Temperature Sensor (3). The PCM will set the fault if it detects that the Aftertreatment DOC is not present in the aftertreatment/exhaust system. The PCM will illuminate the MIL lamp when the monitor runs and fails after one trip. The PCM will turn off the MIL lamp immediately after the diagnostic runs and passes.