PACCAR PX-9 CM2350 (2013-17) Fault Code:1691 PID:1691 SPN:5298 FMI:18 Aftertreatment Diesel Oxidation Catalyst Conversion Efficiency – Data Valid But Below Normal Operating Range – Moderately Severe Level

Reason:
Aftertreatment Diesel Oxidation Catalyst Conversion Efficiency – Data Valid But Below Normal Operating Range – Moderately Severe Level. The temperature increase across the aftertreatment catalyst is lower than expected.

Effect:
Possible frequent need for aftertreatment regeneration

Circuit Description:
The aftertreatment diesel particulate filter temperature sensor module is a smart device that communicates with the engine control module via the J1939 data link. The aftertreatment diesel partculate filter temperature sensor module performs its own internal diagnostics and reports malfunctions back to the engine control module using the J1939 data link. The aftertreatment diesel particulate filter temperature sensor module is used to measure the aftertreatment diesel oxidation catalyst intake temperature, aftertreatment diesel particulate filter intake temperature, and aftertreatment diesel particulate filter outlet temperature. The temperature probes are permanently attached to the aftertreatment diesel particulate filter temperature sensor module and can not be replaced individually.

Component Location:
The aftertreatment diesel oxidation catalyst is located in the exhaust system. The location of the catalyst can vary, depending on the original equipment manufacturer (OEM). Refer to the OEM service manual.

Conditions for Running the Diagnostics:
This diagnostic runs continuously when the engine is running and active regeneration of the aftertreatment diesel particulate filter is occurring.

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) calculated the DOC efficiency was less than required to successfully complete a regeneration.

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.

Conditions for Clearing the Fault Code:
1) To validate the repair, start the engine and perform the INSITE™ electronic service tool Aftertreatment Diesel Particulate Filter Regeneration Test.
2) The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
3) The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
4) The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults.

Shop Talk:
N/A

Possible Causes:
1) A malfunctioning diesel oxidation catalyst
2) A malfunctioning aftertreatment fuel injector