ISX12/ISX11.9 CM2250 Fault Code: 1932 | SPN: 3556 | FMI: 2Aftertreatment Doser – Data Erratic, Intermittent, or Incorrect

Overview

Circuit Description

Before active regeneration of the aftertreatment diesel particulate filter, a diagnostic test on the system is performed. The aftertreatment fuel injector opens and relieves fuel pressure in the line. The aftertreatment fuel pressure sensor must be reading atmospheric pressure at this point in the test. The aftertreatment fuel injector closes and the aftertreatment purge air actuator opens. This pressurizes the aftertreatment fuel system to vehicle air pressure. The diagnostic then checks to make sure the aftertreatment fuel pressure sensor is reading vehicle air pressure. The aftertreatment fuel shutoff valve then opens and allows pressurized fuel to enter the system. The aftertreatment fuel injector then opens and primes the system by purging the air from the line. The aftertreatment fuel shutoff valve and aftertreatment fuel injector then close and trap the fuel between the aftertreatment fuel shutoff valve and the aftertreatment fuel injector. The diagnostic checks to make sure the system maintains fuel pressure.

Component Location

The aftertreatment fuel injector is installed in the exhaust system in the turbocharger adapter pipe. The aftertreatment fuel pressure sensor and aftertreatment fuel shutoff valve are installed in the shutoff valve manifold. The aftertreatment purge air actuator is located above the shutoff valve manifold.

Conditions for Running the Diagnostics

This diagnostic runs during active regeneration of the aftertreatment diesel particulate filter.

Conditions for Setting the Fault Codes

The Engine Control Module (ECM) detected a leaking aftertreatment fuel injector or an external leak.

Action Taken When the Fault Code is Active

• The ECM illuminates the amber CHECK ENGINE lamp and/or the malfunction indicator lamp (MIL) immediately when the diagnostic runs and fails.

Active regeneration of the aftertreatment diesel particulate filter will be disabled unitl the next key cycle.

Engine torque will be reduced if the engine is operated for an extended period of time with this fault active.

Conditions for Clearing the Fault Code

• To validate the repair, start the engine and perform the recommended Cummins® electronic service tool or equivalent Aftertreatment Diesel Particulate Filter Regeneration Test.
• The fault code status displayed by the recommended Cummins® electronic service tool or equivalent will change to INACTIVE immediately after the diagnostic runs and passes.
• The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
• For On-Board Diagnostics (OBD) engines, the ECM will extinguish the Malfunction Indicator Lamp (MIL) after three consecutive trips where the diagnostic runs and passes.
• The “Reset All Faults” command in the recommended Cummins® electronic service tool or equivalent can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications.

Shop Talk

Possible causes of this fault code include:

A stuck open or leaking aftertreatment fuel injector

An external leak in the aftertreatment fuel injector system.

Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring supplied by the OEM.