What is the SCR on a DPF system?

What is Selective Catalytic Reduction? Selective Catalytic Reduction (SCR) is an advanced active emissions control technology system that reduces tailpipe emissions of nitrogen oxides (NOx) down to near-zero levels in newer generation diesel-powered vehicles and equipment.

What is the SCR on Freightliner Cascadia?

A: SCR stands for Selective Catalytic Reduction . SCR simply adds a Diesel Exhaust Fluid (DEF) into the exhaust gas and filters it through a catalyst to convert NOx into nitrogen and water which is released into the air.

What is the difference between SCR and DOC and DPF?

The DPF and DOC filters are suitable for pneumatic and thermal cleaning; conversely, because the SCR is a closed unit it is not suitable for the pneumatic cleaning . It can still get blocked by hardened DEF and if this happens it is not usually serviceable.

What is a doc in a DPF system?

A diesel oxidation catalyst (DOC) is an aftertreatment component that is designed to convert carbon monoxide (CO) and hydrocarbons into carbon dioxide (CO2) and water . The device is used on all our EU Stage IV/U.S. EPA Tier 4 Final products – from the 400F through to the 1206F.

How much does it cost to fix a SCR?

On average, these systems cost around $4,000 to replace on a heavy-duty vehicle.

What happens when an SCR fails?

If an SCR does fail, it typically becomes shorted allowing load current to flow continuously .

What causes SCR system fault?

Unfortunately an SCR fault like this could be many things such as: A faulty nox sensor . A faulty DEF quality sensor. A wiring issue to one of the SCR sensors or components. A faulty DEF pump.

Are SCR and DEF the same?

What is Selective Catalytic Reduction (SCR)? SCR is a technology that uses a urea-based diesel exhaust fluid (DEF) and a catalytic converter to significantly reduce oxides of nitrogen (NOx) emissions.

Which is better, EGR or SCR?

EGR is more effective in small cars where packaging space for Urea tank & injection system is less. SCR is more effective for long wheel base applications . EGR is more effective in low power engine application & not recommended to heavy duty application engines due to its contamination effects.

Can a diesel SCR be cleaned?

As an owner/driver of a Diesel-powered vehicle you need to clean the SCR regularly as this will save you money in operating costs and prevent costly downtime in the long run. Maintenance schedules or cleaning cycles vary according to the type of vehicle and how your vehicle is being used.

What does the SCR do?

Selective Catalytic Reduction (SCR) is a proven and advanced active emissions control technology system that injects a liquid-reductant agent through a special catalyst into the exhaust stream of a diesel engine . The reductant source is usually automotive-grade urea, otherwise known as Diesel Exhaust Fluid (DEF).

Detroit Diesel DD13, DD15 fault codes for DPF, DOC, SCR, Catalyst replacement needed. (2024)

SPN 3056 FMI 2Selective Catalyst Reduction Inlet NOx Sensor – Error
SPN 3057 FMI 2Selective Catalyst Reduction Outlet NOx Sensor – Error
SPN 3216 FMI 3Selective Catalyst Reduction Inlet NOx Sensor Circuit Failed High
SPN 3216 FMI 4Selective Catalyst Reduction Inlet NOX Sensor Circuit Failed Low
SPN 3216 FMI 10Selective Catalyst Reduction Inlet NOx sensor – Signal Erratic
SPN 3216 FMI 13Selective Catalyst Reduction Inlet NOx Sensor Signal Not Available
SPN 3216 FMI 16Selective Catalyst Reduction Inlet NOx Sensor – Drift High
SPN 3216 FMI 18Selective Catalyst Reduction Inlet NOx Sensor – Drift Low
SPN 3216 FMI 21Selective Catalyst Reduction (SCRA) Inlet NOx Sensor – Drift (Low Box)
SPN 3217 FMI 3Selective Catalyst Reduction Inlet NOx Sensor Circuit Failed High
SPN 3217 FMI 5Selective Catalyst Reduction Inlet NOx Sensor Circuit Failed Open
SPN 3226 FMI 13Selective Catalyst Reduction Outlet NOx Sensor Signal Not Available
SPN 3226 FMI 20Selective Catalyst Reduction Outlet NOx Sensor – Drive Low
SPN 3227 FMI 3Selective Catalyst Reduction Outlet NOx Sensor Circuit Failed High
SPN 3227 FMI 5Selective Catalyst Reduction Outlet NOx Sensor Circuit Failed Open
SPN 3238 FMI 2Selective Catalyst Reduction Outlet NOx Sensor Failure to Activate
SPN 3242 FMI 3Diesel Oxidation Catalyst Inlet Temperature Sensor Circuit Failed High
SPN 3242 FMI 4Diesel Oxidation Catalyst Inlet Temperature Sensor Failed Low
SPN 3242 FMI 7Diesel Oxidation Catalyst Inlet Temperature – Signal Not Responding
SPN 3242 FMI 8Diesel Oxidation Catalyst Inlet Temperature – Signal Spike
SPN 3242 FMI 17Diesel Oxidation Catalyst Inlet Temperature Out of Range Low Preventing HC Dosing
SPN 3242 FMI 20Diesel Oxidation Catalyst Temperature Drift – Inlet High or Outlet Low
SPN 3246 FMI 0Diesel Particulate Filter Outlet Temperature – Very High
SPN 3246 FMI 3Diesel Particulate Filter Outlet Temperature Sensor Circuit Failed High
SPN 3246 FMI 4Diesel Particulate Filter Outlet Temperature Sensor Circuit Failed Low
SPN 3246 FMI 8Diesel Particulate Filter Outlet Temperature – Signal Spike
SPN 3246 FMI 15Diesel Particulate Filter Outlet Temperature – High
SPN 3246 FMI 20Diesel Particulate Filter Outlet Temperature Sensor Stuck
SPN 3246 FMI 21Diesel Particulate Filter Outlet Temperature Sensor – Not Plausible
SPN 3246 FMI 7DPF Outlet Temperature Sensor Not Responding
SPN 3246 FMI 2DPF Outlet Temperature Not Plausible
SPN 3250 FMI 0Diesel Oxidation Catalyst Outlet Temperature Very High
SPN 3250 FMI 3Diesel Oxidation Catalyst Outlet Temperature Circuit Failed High
SPN 3250 FMI 4Diesel Oxidation Catalyst Outlet Temperature Circuit Failed Low
SPN 3250 FMI 7Diesel Oxidation Catalyst Outlet Temperature Circuit Failed Low
SPN 3250 FMI 8Diesel Oxidation Catalyst Outlet Temperature – Signal Spike
SPN 3250 FMI 15Diesel Oxidation Catalyst Outlet Temperature High
SPN 3250 FMI 20Diesel Oxidation Catalyst Temperature Drift – Inlet Low or Outlet High
SPN 3250 FMI 31Abnormal Diesel Oxidation Catalyst Temperature Rise
SPN 3251 FMI 0Diesel Particulate Filter Pressure Out of Range Very High
SPN 3251 FMI 1Diesel Particulate Filter Pressure Out of Range Low
SPN 3251 FMI 16Diesel Particulate Filter Pressure Out of Range High
SPN 3251 FMI 20Diesel Oxidation Catalyst Inlet Pressure – Not Plausible
SPN 3251 FMI 21Diesel Oxidation Catalyst Inlet/Outlet Pressure – Not Plausible
SPN 3609 FMI 3Diesel Oxidation Catalyst Inlet Pressure Sensor Circuit Failed High
SPN 3609 FMI 4Diesel Oxidation Catalyst Inlet Pressure Sensor Circuit Failed Low
SPN 3610 FMI 3Diesel Particulate Filter Outlet Pressure Sensor Circuit Failed High
SPN 3610 FMI 4Diesel Particulate Filter Outlet Pressure Sensor Circuit Failed Low
SPN 3610 FMI 2Diesel Oxidation Catalyst Inlet Pressure – Not Plausible
SPN 3695 FMI 9DPF Regen Inhibit MUX Switch Message Stopped Arriving
SPN 3695 FMI 13DPF Regen Inhibit MUX Switch Message Contains SNV Indicator
SPN 3695 FMI 14DPF Regen Inhibit MUX Switch Message Not Received this Ign Cycle
SPN 3695 FMI 19DPF Regen Inhibit MUX Switch Message Contains Data Error Indicator
SPN 3696 FMI 4Diesel Particulate Filter Regeneration Switch Short Circuit to Ground
SPN 3696 FMI 9Diesel Particulate Filter Regen Force MUX Switch Message Stopped Arriving
SPN 3696 FMI 13Diesel Particulate Filter Regen Force MUX Switch Message Contains SNV Indicator
SPN 3696 FMI 14Diesel Particulate Filter Regen Force MUX Switch Message Not Received this Ignition Cycle
SPN 3696 FMI 19Diesel Particulate Filter Regen Force MUX Switch Message Contains Data Error Indicator
SPN 3719 FMI 15Diesel Particulate Filter Zone 3 Condition
SPN 3719 FMI 31Silent Code That Logs When the Diesel Particulate Filter Regeneration Lamp is Flashing in ” Regen Zone 2″.
SPN 3719 FMI 0DPF Filter Soot Level is Very High
SPN 3719 FMI 16DPF Filter Soot Level is High
SPN 3720 FMI 15Diesel Particulate Filter Has Reached the End of its Service Life
SPN 3936 FMI 18Diesel Particulate Filter (DPF) Pressure – Out of Range Low
SPN 4332 FMI 31DOC Inlet Temperature Out of Range Low Preventing Dosing
SPN 4360 FMI 2Selective Catalyst Reduction Inlet Temperature – Not Plausible
SPN 4360 FMI 3Selective Catalyst Reduction Inlet Temperature Sensor Circuit Failed High
SPN 4360 FMI 4Selective Catalyst Reduction Inlet Temperature Sensor Circuit Failed Low
SPN 4360 FMI 8Selective Catalyst Reduction (SCR) Inlet Temperature Signal Spike
SPN 4360 FMI 15Selective Catalyst Reduction Inlet Temperature High
SPN 4360 FMI 20Selective Catalyst Reduction Inlet Temperature Sensor Drift High in Range
SPN 4360 FMI 31Selective Catalyst Reduction Inlet Temperature Not Warming Up
SPN 4363 FMI 2Selective Catalyst Reduction Outlet Temperature – Not Plausible
SPN 4363 FMI 3Selective Catalyst Reduction Outlet Temperature Sensor Circuit Failed High
SPN 4363 FMI 4Selective Catalyst Reduction Outlet Temperature Sensor Circuit Failed Low
SPN 5018 FMI 18Diesel Oxidation Catalyst Efficiency Fault
SPN 5298 FMI 14Selective Catalytic Reduction Catalyst Abnormal Temperature Rise
SPN 5323 FMI 13Excessive Time to Enter Closed Loop Fuel Pressure Control
SPN 5443 FMI 0DPF HC Absorption Very High
SPN 5443 FMI 15DPF HC Absorption Warning SPN
SPN 5443 FMI 16DPF HC Absorption High
SPN 5488 FMI 5Selective Catalyst Reduction Line Heater 5 Circuit Failed Open
SPN 520232 FMI 9NOx Mass Signal Not Available via Controller Area Network
SPN 520323 FMI 3High Side Digital Output Circuit Failed High
SPN 520323 FMI 4High Side Digital Output Circuit Failed Low
SPN 520326 FMI 3Under Pressurized Diesel Exhaust Fluid System
SPN 520326 FMI 4Over Pressurized Diesel Exhaust Fluid (DEF) System
SPN 520327 FMI 3Under Pressurized Diesel Exhaust Fluid System
SPN 520327 FMI 4Over Pressurized Diesel Exhaust Fluid System
SPN 520328 FMI 7Diesel Exhaust Fluid System has Been Over-Pressurized
SPN 520329 FMI 31Non Diesel Exhaust Fluid Flow Situation
SPN 520332 FMI 17Diesel Oxidation Catalyst Inlet Temperature Out of Range Low Preventing HC Dosing
SPN 520349 FMI 14DPF Filtration Efficiency Low
SPN 520363 FMI 3Selective Catalyst Reduction Inlet NOx Sensor Circuit Failed High
SPN 520363 FMI 5Selective Catalyst Reduction Inlet NOx Sensor Circuit Failed Open
SPN 520364 FMI 3Selective Catalyst Reduction Inlet NOx Sensor Circuit Failed High
SPN 520365 FMI 3Selective Catalyst Reduction Outlet NOx Sensor Circuit Failed High
SPN 520365 FMI 5Selective Catalyst Reduction Outlet NOx Sensor Circuit Failed Open
SPN 520366 FMI 3Selective Catalyst Reduction Outlet NOx Sensor Circuit Failed High
SPN 520366 FMI 5Selective Catalyst Reduction Outlet NOx Sensor Circuit Failed Open
SPN 520367 FMI 3Selective Catalyst Reduction Inlet NOx Sensor Circuit Failed High
SPN 520367 FMI 5Selective Catalyst Reduction Inlet NOx Sensor Circuit Failed Open
SPN 520368 FMI 14Selective Catalyst Reduction Outlet NOx Sensor Circuit Failed Open
SPN 520368 FMI 31Selective Catalyst Reduction Outlet NOx Sensor Circuit Failed High
SPN 520371 FMI 16Selective Catalyst Reduction Closed Loop Control at Maximum Limit (Multiples Sources)
SPN 520372 FMI 14Selective Catalyst Reduction Closed Loop Control at Maximum Limit (Timeout)
SPN 520372 FMI 16Selective Catalyst Reduction Closed Loop Control at Maximum Limit
SPN 524285 FMI 4CM1 DPF Regeneration Switch Short Circuit to Ground
SPN 630 FMI 13Selective Catalytic Reduction Number Out of Range
SPN 3216 FMI 2Selective Catalyst Reduction Inlet NOx Sensor Rationality Error
SPN 3226 FMI 2Selective Catalyst Reduction Outlet NOx Sensor – Drift
SPN 3226 FMI 3Selective Catalyst Reduction Outlet NOx Sensor Circuit Failed High
SPN 3226 FMI 4Selective Catalyst Reduction Outlet NOx Sensor Circuit Failed Low
SPN 3226 FMI 21NOx Outlet Sensor Drift High
SPN 3361 FMI 31Diesel Exhaust Fluid Dosing Unit Error
SPN 3556 FMI 0Regeneration Temperature – Out of Range High
SPN 3556 FMI 1Regeneration Temperature – Out of Range Low
SPN 3556 FMI 18Diesel Oxidation Catalyst Outlet Temperature Low (Low Temp Regeneration)
SPN 3711 FMI 31High Idle Regeneration (Aborted) – Low Exhaust Temperature
SPN 3713 FMI 31High Idle Regeneration Aborted – Low Regeneration Temperature
SPN 4360 FMI 10Selective Catalyst Reduction Inlet Temperature Sensor – Rationality Error
SPN 4363 FMI 0SCR Outlet Temperature High
SPN 4363 FMI 8SCR Outlet Temperature Signal Spike
SPN 4363 FMI 20SCR Temperature Drift – Inlet Low/Outlet High
SPN 4364 FMI 18SCR NOx Conversion Efficiency Low
SPN 5246 FMI 15Regulatory Fault Ignored – Derate On
SPN 5312 FMI 7Intake Manifold Pressure Low
SPN 5435 FMI 7Non Diesel Exhaust Fluid Flow Situation

<# if ( 'one' === design.form_layout ) { #><# if ('' !== content.main_content ||( _.isTrue( content.use_feature_image ) && '' !== content.feature_image ) ||( _.isTrue( content.has_title ) && ( '' !== content.title || '' !== content.sub_title ) ) ||( _.isTrue( content.show_cta ) && '' !== content.cta_label )) { #>

<# if ( ( 'left' === design.feature_image_position || 'above' === design.feature_image_position ) && _.isTrue( content.use_feature_image ) && '' !== content.feature_image ) { #>

<# if ( 'contain' === design.feature_image_fit || 'cover' === design.feature_image_fit ) { #><# if ( 'custom' !== design.feature_image_horizontal || 'custom' !== design.feature_image_vertical ) { #><# } else { #><# } #><# } else { #><# } #>

<# } #><# if (( _.isTrue( content.has_title ) && ( '' !== content.title || '' !== content.sub_title ) ) ||'' !== content.main_content ||( _.isTrue( content.show_cta ) && '' !== content.cta_label )) { #>

<# if ( _.isTrue( content.has_title ) && ( '' !== content.title || '' !== content.sub_title ) ) { #>

<# if ( '' !== content.title ) { #><# } #><# if ( '' !== content.sub_title ) { #>

<# } #>

<# } #>{{{ content.main_content }}}<# if ( _.isTrue( content.show_cta ) && ( '' !== content.cta_label && '' !== content.cta_url ) ) { #>

<# } #>

<# } #><# if ( ( 'right' === design.feature_image_position || 'below' === design.feature_image_position ) && _.isTrue( content.use_feature_image ) && '' !== content.feature_image ) { #>

Detroit Diesel DD13, DD15 fault codes for DPF, DOC, SCR, Catalyst replacement needed. (2024)

{{ content.sub_title }}

{{ content.sub_title }}

{{ content.sub_title }}

{{ content.sub_title }}

FAQs

What is the SCR on a DPF system? ›

What does the SCR do? ›

References