CM2150 Electronic Control System – FAULT CODE 1922

  Printable Version

Overview

ISB, ISC, and ISL – Aftertreatment System SMALL | MEDIUM | LARGE

Circuit Description

The engine aftertreatment system monitors the soot load in the aftertreatment diesel particulate filter. Under normal operating conditions, the aftertreatment diesel particulate filter is self-cleaning, where soot is converted to carbon dioxide, nitrogen, and water. Under light load operating conditions, it can be necessary to perform a stationary regeneration of the aftertreatment diesel particulate filter. The soot load in the aftertreatment diesel particulate filter is estimated, using the aftertreatment differential pressure sensor and the calculated soot output of the engine.

This fault code can be triggered if the application is not operating at a duty cycle that is high enough to actively regenerate the aftertreatment diesel particulate filter. This fault code indicates that the exhaust temperatures exiting the turbocharger are not high enough to actively regenerate the soot that is trapped in the aftertreatment diesel particulate filter. It can be necessary to increase the duty cycle of the application in order to prevent plugging of the aftertreatment diesel particulate filter.

Component Location

The aftertreatment diesel particulate filter is located in the exhaust system, and is installed by the original equipment manufacturer (OEM). Refer to the OEM service manual.

Conditions for Running the Diagnostics

This diagnostic runs continuously when the engine speed is greater than 500 rpm.

Conditions for Setting the Fault Codes

The electronic control module (ECM) detects that the soot load of the aftertreatment diesel particulate filter has exceeded the maximum operating limits.

Action Taken When the Fault Code is Active

• The ECM will illuminate the red STOP ENGINE light immediately after the diagnostic runs and fails.
• Active and stationary regeneration of the diesel particulate filter will be disabled.
• A severe torque derate will be applied to the output of the engine
  (Note: There is no derate in emergency vehicle calibrations).
• Engine speed will be limited to 1800 rpm (ISB CM2150 engines) or 1500 rpm (ISC and ISL CM2150 engines). (Note: There is no derate in emergency vehicle calibrations).

Conditions for Clearing the Fault Code

The ECM will turn off the red STOP ENGINE light immediately after the soot load in the aftertreatment diesel particulate filter has dropped below the most severe level.

Use INSITE™ electronic service tool to perform the Aftertreatment Diesel Particulate Filter Maintenance Reset Test to change Fault Code 1922 to an inactive state after inspecting, cleaning, or replacing the aftertreatment diesel particulate filter.

Shop Talk

Verify the electronic control module (ECM) calibration is correct. Check the calibration revision history found on QuickServe™ Online for applicable fixes to the calibration stored in the ECM. If necessary, calibrate the ECM. Refer to Procedure 019-032 in Section 19.

This fault code indicates that the soot load inside the aftertreatment diesel particulate filter has reached the maximum level, soot level stage 4. Regeneration of the aftertreatment diesel particulate filter at this stage is not possible. The aftertreatment diesel particulate filter must be inspected. If it meets the inspection criteria, it can be cleaned using an SPX air pulse, or equivalent, cleaning machine. If it does not meet the inspection criteria, it must be replaced.

If Fault Code 1922 is active at the same time as Fault Code 1981, it is necessary to clear Fault Code 1981 by following the troubleshooting tree for that fault, then referencing the steps for troubleshooting and clearing Fault Code 1922, below.

Note: Repeated occurrences of this fault code may indicate the engine requires frequent regeneration. Refer to symptom tree t147 (Aftertreatment Diesel Particulate Filter-Excessive Automatic and/or Stationary Regeneration) to identify the cause of frequent regeneration.

Possible causes of this fault code include:

• The aftertreatment wiring harness connectors may be connected to the wrong aftertreatment temperature sensors.
• The aftertreatment wiring harness or aftertreatment temperature sensor connector pin installation may be incorrect.
• The engine has been operating in a light load condition that prevents exhaust temperatures from being high enough to actively regenerate the aftertreatment diesel particulate filter.
• A possible base engine malfunction that causes excessive black soot to be generated.
• If both Fault Code 1921 and 2777 are inactive with an active Fault Code 1922, this indicates that a regeneration inhibit message had been received by the engine ECM and that active regeneration of the aftertreatment diesel particulate filter was not allowed. Use the OEM service information to confirm that the OEM settings for the aftertreatment permit switch are configured correctly.

The aftertreatment diesel particulate filter soot loading can be classified into four different stages. As the soot load increases, the aftertreatment diesel particulate filter lamp and the Cummins® CHECK ENGINE (Amber) or STOP ENGINE (Red) lamp will operate according to the table below. Inadequate temperature for the exhaust gases entering the aftertreatment system can be a cause of high soot loads in the aftertreatment diesel particulate filter. The duty cycle of the application may need to be increased in order to prevent excessive soot from accumulating in the filter.

Refer to Troubleshooting Fault Code t05-1922.