CM2150 Electronic Control System – FAULT CODE 2777

Particulate Trap Active Regeneration Inhibited Due to Permit Switch – Condition Exists


Fault Code: 2777
PID: 390
SPN: 3703
FMI: 11/31
LAMP: None

Particulate Trap Active Regeneration Inhibited Due to Permit Switch – Condition Exists. Regeneration of the diesel particulate filter has been prevented due to the permit switch being disabled.

None on performance.

Aftertreatment System

Circuit Description

The OEM truck manufacturer may install a permit switch in the dash or send an inhibit message via the J1939 datalink to the engine ECM. The function of the inhibit message is to prevent the aftertreatment system from performing mobile regenerations. The purpose of this fault code is to inform the technician that the permit switch was disabled when Fault Code 1921, 1922, or 2639 was set active. This fault code may indicate the reason that high aftertreatment soot load fault codes are logged.

Component Location

The aftertreatment diesel particulate filter is located in the exhaust system and is installed by the original equipment manufacturer (OEM). The permit switch may be an actual switch in the vehicle dash or it may be a J1939 message sent via the J1939 datalink. Refer to the OEM troubleshooting and repair manual.

Conditions for Running the Diagnostics

This diagnostic runs continuously when the keyswitch is in the on position.

Conditions for Setting the Fault Codes

This fault code is triggered if the permit switch is disabled when Fault Code 1921, 1922, or 2639 is activated for high soot load levels in the diesel particulate filter.

Action Taken When the Fault Code is Active

The ECM will set the fault code active immediately after the diagnostic is set.

Conditions for Clearing the Fault Code

The fault code will be set inactive when Fault Code 1921, 1922, or 2639 are set inactive.

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, recalibrate the ECM. Refer to Procedure 019-032 (ECM Calibration Code) in Section 19 in the corresponding Troubleshooting and Repair Manual for the engine being serviced.

If this fault code is active and there has been damage to the aftertreatment system, the permit switch may have prevented the aftertreatment system from performing a mobile (active) regeneration. Consult with the OEM if the aftertreatment system has failed due to the permit switch.

Refer to Troubleshooting Fault Code t05-2777

Last Modified:  20-Jul-2010