Overview

 

CODE REASON EFFECT
Fault Code: 6646
PID: 
SPN: 5569
FMI: 2/2
LAMP: Amber
SRT: 

 

Erratic internal temperatures have been detected by the aftertreatment particulate sensor.

 

 

Possible reduced engine performance.

Circuit Description

The aftertreatment particulate matter sensor is a smart device and communicates with the engine control module (ECM) via the J1939 data link. The aftertreatment particulate matter sensor performs internal diagnostics and reports malfunctions back to the primary ECM using the J1939 data link. The particulate matter sensor is permanently attached to the particulate matter control module. They are serviced as a single component and can not be replaced individually. The aftertreatment particulate matter sensor is used to measure the soot emissions at the outlet of the aftertreatment system.

Component Location

The aftertreatment particulate matter sensor location can vary depending on engine application. It is usually located in the exhaust system at the outlet of the selective catalytic reduction (SCR) catalyst.

 

Conditions for Running the Diagnostics

This diagnostic runs continuously when the engine is running.

Conditions for Setting the Fault Codes

The aftertreatment particulate matter sensor has detected a mismatch between the internal ECU temperature probes.

Action Taken When the Fault Code is Active

  • The ECM illuminates the amber CHECK ENGINE lamp and/or malfunction indicator lamp (MIL) after the diagnostic fails on two consecutive trips.

Conditions for Clearing the Fault Code

  • 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:

  • Malfunctioning aftertreatment particulate matter sensor

Solution: S00000040

Verification

Conditions

  • Turn keyswitch ON.
  • Connect the recommended Cummins® electronic service tool or equivalent.

Action

  • Use the recommended Cummins® electronic service tool or equivalent to read the fault codes.

Specification

Before troubleshooting this fault code, troubleshoot any fault code that is active or has more than one inactive count within the last 25 engine operating hours from the following list:

  • Aftertreatment Particulate sensor: 5582, 5583, 6651, 6652, 6653, 6688

Linked Solutions

  • None

Repair

  • Perform a search on the appropriate fault codes.

Validation

  • None

Solution: S00000443

Verification

Conditions

  • Connect all components.
  • Turn keyswitch ON.
  • Connect the recommended Cummins® electronic service tool or equivalent.

Action

  • Use the recommended Cummins® electronic service tool or equivalent to read the fault codes.
  • Use the recommended Cummins® electronic service tool or equivalent to find the current ECM code and revision number in the ECM.
  • Compare the ECM code and revision number in the ECM to the calibration revision listed in the ECM calibration revision history for applicable changes.

Specification

  • If a calibration update for this fault code is available, the ECM calibration revision must be that revision or higher.

Linked Solutions

  • None

Repair

  • Prior to downloading the ECM calibration, check to see that all job images and all other troubleshooting has been documented as downloading an ECM calibration will remove the fault codes on the ECM.
  • Download the updated ECM calibration code.

Refer to Procedure 019-032

Validation

  • Connect all components
  • Connect the recommended Cummins® electronic service tool or equivalent.
  • Disable the fault code.
  • Operate the engine within the “Conditions for Clearing the Fault Code” found in the Overview section of the troubleshooting procedure.
  • Verify that the fault code is no longer active.
  • Check ECM Calibration Revision History
  • Use the recommended Cummins® electronic service tool or equivalent to find the current ECM code and revision number in the ECM.
  • Compare the ECM code and revision number in the ECM to the calibration revisions listed in the ECM Calibration Revision History Database for applicable changes related to this fault code.
  • Refer to ECM Calibration Revision History Database.

Solution: S00007912

Verification

Conditions

  • Turn keyswitch ON.
  • Connect the recommended Cummins® electronic service tool or equivalent.

Action

  • Use the recommended Cummins® electronic service tool or equivalent to read the fault codes.
  • Verify all preceding solution verifications for this fault code have been performed.

Specification

  • If the fault code is still active or inactive with more than one count within the last 25 engine hours and all the preceding solution verifications have been performed, then proceed to the Repair section.

Linked Solutions

  • None

Repair

Repair or replace only the components that were found to be out of specification.

  • Replace the aftertreatment particulate sensor.

Refer to Procedure 019-478

Validation

  • Connect all components
  • Connect the recommended Cummins® electronic service tool or equivalent.
  • Disable the fault code.
  • Operate the engine within the “Conditions for Clearing the Fault Code” found in the Overview section of the troubleshooting procedure.
  • Verify that the fault code is no longer active.
  • Check ECM Calibration Revision History
  • Use the recommended Cummins® electronic service tool or equivalent to find the current ECM code and revision number in the ECM.
  • Compare the ECM code and revision number in the ECM to the calibration revisions listed in the ECM Calibration Revision History Database for applicable changes related to this fault code.
  • Refer to ECM Calibration Revision History Database.

If all steps have been completed and no root cause has been identified, then follow the technical escalation process.

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