OBD Operation Summary for 6.7L Diesel - MotorCraftService.com

NON-METHANE HYDROCARBON (NMHC) CONVERTING CATALYST MONITORDiesel Oxidation Catalyst Efficiency MonitorThe Diesel Oxidation Catalyst (DOC) is monitored to ensure it is capable of converting hydrocarbons and carbonmonoxide. The monitor is only run during aftertreatment regeneration events. After entering regen, there is a shortdelay to allow the DOC to achieve light-off temperature. Then the exotherm is monitored for a short period of timeand normalized versus an expected exotherm (a function of post-injection fuel quantity and ambient air temp). Theexotherm is defined as the DOC outlet temperature (EGT12) minus the DOC inlet temperature (EGT11). Thenormalized exotherm is filtered for a short period of time, and then compared to a threshold. If the normalizedexotherm is below the threshold, a fault is indicated. No other preconditioning is required.DOC Efficiency Monitor Summary:DTCsMonitor executionMonitor SequenceSensors OKMonitoring DurationP0420 – Catalyst System Efficiency Below ThresholdOnce per driving cycle during which an active DPF regeneration occursNoneEGT11, EGT12, TCO, MAF, IAT4 minutesTypical DOC Efficiency Monitor Entry Conditions:Entry condition Minimum MaximumDPF regeneration eventEngine speed 1000 rpm 3000 rpmTorque set point 100 Nm 1000 NmEngine coolant temperature70 deg CDOC inlet temperature 200 deg C 500 deg CPTO inactiveTypical DOC Efficiency Monitor Malfunction Threshold:Normalized exotherm is less than 40% of the expected exotherm for 60 secondsFORD MOTOR COMPANY REVISION DATE: FEBRUARY 9, 2012 09.01.00.02-PAGE 13 OF 157