C15 and C18 – Clean Emissions Module Regeneration Types and Operating Criteria

Automatic Regenerations
Automatic regenerations are designed so that no input is needed from the operator. There are two types of automatic regeneration. These regenerations are referred to as low speed regeneration and high speed regeneration. Low speed regeneration and high speed regeneration must meet certain criteria before the regeneration will automatically activate. This criteria is outlined below. Certain aspects of automatic regeneration can be configured though Cat ET. These aspects are discussed later in this section.

Low Speed Regeneration

Low speed regeneration occurs when the engine is in a stationary or non-working condition. Low speed regenerations will typically occur between 30 percent and 65 percent soot level. The regenerations can occur up to 116% soot level. Low speed regenerations allow for the most precise control of fuel and airflow. Low speed regenerations require the least amount of fuel to be used as well as having the lowest duration times. The parameters listed below must be met to activate the low speed regeneration.

Active Diagnostic or Event Codes – no active diagnostic or event codes can be active for the ARD fuel system, ARD air system, or ARD ignition system
Engine Coolant Temperature – the engine coolant temperature must be greater than 40° C (104° F) if the ambient air temperature is greater than 0° C (32° F). If the ambient air temperature is less than 0° C (32° F), coolant temperature must be 60° C (140° F)
Engine Startup Delay – the engine must be running for at least 2 minutes after a startup before regeneration will be allowed
DPF Inlet Temperature – the DPF inlet temperature must be greater than 50C (122F)
Engine Speed

Engine speed must be within the low idle speed setting and 1500 rpm. If engine speed exits this window for 1 second, the regeneration will terminate. If the ambient temperature is less than -18° C (-0° F), engine speed must be within the range of low idle speed to 1600 rpm.

Fuel Delivery

Delivered fuel volume must be within 10 and 80 cubic millimeters of fuel for the C9.3 and C13 Engines. Delivered fuel volume must be within 10 and 100 cubic millimeters for C15 and C18 Engines. If fuel delivery exits this window for 1 to 2 seconds, the regeneration will terminate. Delivered fuel volume may be as high as 200 cubic millimeters for Industrial applications.

Engine Speed Control During Low Speed Regeneration

If the programmed low idle engine speed is less than 1000 rpm, the engine CEM may automatically elevate engine speed. The speed will be elevated to between 1000 and 1500 rpm. This change is needed to provide adequate airflow for regeneration. The elevated engine speed may remain for 30 seconds after the regeneration active lamp has turned off. In order for the engine ECM to elevate engine idle speed, pin 46 on the J1/P1 connector must be grounded. This connection can be hard wired to ground, or run through a switch that will connect the pin to ground when pressed. If pin 46 on the J1/P1 engine ECM connector is not grounded, engine speed will not elevate and regeneration will not occur.

Note: If a switch is used, the switch must be on continuous. A momentary switch will not keep the pin grounded for the duration that is needed.

High Speed Regeneration

High speed regeneration typically occurs when the engine is in normal operating mode. High speed regenerations typically consume more fuel and require more time to complete compared to low speed regenerations. This longer time requirement is due to maintaining lower desired DPF inlet temperatures to avoid damaging the DPF from extreme changes in temperature. High speed regeneration has two distinct operating regions. These operating regions are determined by the soot level. The first region is between 60 and 80 percent soot level, the second region is between 80 and 90 percent soot level. The 60 to 80 percent region has a tighter engine operating mode in which high speed regeneration can occur. The 80 to 90 percent region opens the engine operating mode to allow for the highest opportunity to perform a high speed regeneration. High speed regenerations will not occur when the soot level is greater than 90 percent. The parameters listed below outline the operating criteria that are monitored to activate and sustain high speed regeneration.

In order for high speed regenerations to take place, pin 47 on the J1/P1 connector on the engine ECM must be grounded. This connection can be hard wired to ground or grounded through a switch. A switch is provided on the Cat instrument panels. Refer to the Operation and Maintenance Manual, “Diesel Particulate Filter Regeneration” for more information.

Note: All of the parameters listed below are independently developed for each application. All applications may not meet the exact criteria outlined below.

The following parameters must be met for regeneration to occur:

Active Diagnostic or Event Codes – no active diagnostic or event codes can be active for the ARD fuel system, ARD air system, or ARD ignition system
Engine Coolant Temperature – the engine coolant temperature must be greater than 40° C (104° F) if the ambient air temperature is greater than 0° C (32° F). If the ambient air temperature is less than 0° C (32° F), coolant temperature must be 60° C (140° F)
Engine Startup Delay – the engine must be running for at least 2 minutes after a startup before regeneration will be allowed
DPF Inlet Temperature – the DPF inlet temperature must be greater than 50C (122F)
Engine speed (60-80% soot level)

Engine speed is typically between 1400 and 2200 rpm. Engine speed should not change more than 200 rpm per second.

Engine speed (80-90% soot level)

Engine speed is typically between 975 and 2350 rpm. Engine speed should not change more than 400 rpm per second.

Fuel Delivery (60-80% soot level)

Delivered fuel volume is typically between 30 cubic millimeters and an upper limit defined by the engine power rating.


(X) Engine speed

(Y) Delivered Fuel Volume

(Z) Example of engine operating region for high speed regeneration (60-80% soot level)

Fuel Delivery (80-90% soot level)

Delivered fuel volume is typically between 10 cubic millimeters and an upper limit defined by the engine power rating. In this soot level range, the upper fuel limit is the torque fuel limit volume at each rpm.

Combustion Air Inlet Pressure (60-80% soot level)

The combustion air inlet pressure should not change more than 65 kPa (9.4 psi) per second.

Combustion Air Inlet Pressure (80-90% soot level)

The combustion air inlet pressure should not change more than 80 kPa (11.6 psi) per second.

Engine Speed Control during High Speed Regeneration

Most aspects of high speed regeneration are transparent. If the engine is in normal working mode and the throttle is released, the low idle will be limited to 1000 rpm. Limiting the engine speed to 1000 rpm will maintain the regeneration. If the engine speed must be brought to the programmed low idle speed, pressing the disable regen switch will stop the regeneration. The engine will return engine speed to the programmed low idle speed.

Manual Regenerations
Manual regeneration is accomplished by pressing the force regeneration switch. Manual regenerations can be performed when soot level is between 15 and 116 percent. Manual regenerations are performed by pressing the force regeneration switch for 2 seconds. Refer to the Operation and Maintenance Manual, “Diesel Particulate Filter Regeneration” for more information. Manual regenerations can be done in the low speed regeneration region outlined above. All criteria described above is applicable to a manual regeneration in the low speed regeneration region.

Manual regenerations can be performed in the high speed regeneration region. However, the fuel delivery and engine speed thresholds are slightly modified from what is described above. The values are as follows:

Engine Speed: 1400-2200 rpm
Fuel Delivery: minimum 30 mm3 up to a maximum of 175 mm3 for C9.3 and C13 engines and 300mm3 for C15 and C18 engines. The upper limit may vary slightly depending on engine rating.

Aftertreatment Configuration Parameters
The aftertreatment system can be configured differently to suit the operation that the system is being used in. Configurations are also needed to assure the correct CEM is connected to the correct engine. The available configurations and the functions are the following:

ARD manual disable status

This status will disable all regenerations from occurring. Automatic and Manual regenerations will not work with this parameter set to “DISABLED”. This parameter should be set to “NOT DISABLED” under normal conditions. This parameter is beneficial when servicing the system and regenerations are not desired.

ARD auto regeneration enable status

This configuration has three settings. The settings are ENABLED, DISABLED, AND AUTOMATIC LOW SPEED REGENERATION ONLY. When configuration is set to ENABLED, all types of regeneration are available. When the configuration is set to DISABLED, only Manual regenerations will be available. When configuration is set to AUTOMATIC LOW SPEED REGENERATION ONLY, high speed regeneration is not available. Low speed regeneration and manual regenerations are still available.

Factory Installed Aftertreatment #1 Identification Number

This configuration contains the serial number of the CEM that is attached to the engine. This configuration is automatically programmed during initial assembly of the CEM to the engine. If this parameter needs re-entered, the serial number can be found on the identification plate attached to the CEM.

DPF #1 Soot loading Sensing system configuration code

This configuration contains a two-digit code which notifies the engine ECM what type of DPF configuration is used. Different DPF inlet and outlet orientations affect the Radio frequency output provided by the RF soot sensors. This code ensures the engine ECM is using the appropriate calibration to interpret the soot sensor signal.

High Soot Load Aftertreatment protection enable status

This configuration is ENABLED by default. This configuration will activate the forced low idle speed strategy and forced engine shutdown strategy for high soot loading events. If this feature is “DISABLED”, the forced low idle strategy and the forced engine shutdown strategy will not activate. These strategies must activate in the event of high soot loading.

Posted in C18

Leave a Reply

Your email address will not be published. Required fields are marked *