PACCAR PX-9 CM2350 (2013-17) Fault Code:2976 PID: SPN:3361 FMI:2 Aftertreatment 1 Diesel Exhaust Fluid Dosing Unit Temperature – Data Erratic, Intermittent, or Incorrect

Reason:
Aftertreatment Diesel Exhaust Fluid Dosing Unit Temperature – Data Erratic, Intermittent, or Incorrect. An internal error has been detected in the aftertreatment diesel exhaust fluid dosing unit.

Effect:
Possible reduced engine performance.

Circuit Description:
The aftertreatment diesel exhaust fluid dosing unit precisely measures the amount of aftertreatment diesel exhaust fluid to be injected into the aftertreatment system. The aftertreatment diesel exhaust fluid dosing unit has three primary cycles. A priming cycle makes sure that aftertreatment diesel exhaust fluid is available at the aftertreatment diesel exhaust fluid dosing unit. During the dosing cycle, aftertreatment diesel exhaust fluid is being delivered to the aftertreatment dosing valve. A purge cycle occurs when the engine is turned OFF. The purge cycle makes sure that all the aftertreatment diesel exhaust fluid is removed from the diesel exhaust fluid lines and dosing valve.

Component Location:
The aftertreatment diesel exhaust fluid dosing unit location is original equipment manufacturer (OEM) dependent. Refer to the OEM service manual.

Conditions for Running the Diagnostics:
This diagnostic runs immediately after the keyswitch is turned to the ON position, and continues until the diesel exhaust fluid dosing unit attempts to prime.

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected the aftertreatment diesel exhaust fluid dosing unit internal temperature was not communicated to the ECM by the diesel exhaust dosing unit.

Action Taken When the Fault Code is Active:
1) The ECM illuminates the amber CHECK ENGINE lamp and/or Malfunction Indicator Lamp (MIL) after the diagnostic fails on two consecutive trips.
2) Diesel exhaust fluid injection into the aftertreatment system is disabled.
3) Engine torque will be reduced if the engine is operated for an extended period of time with this fault active.
4) Vehicle speed will be limited to 8 km [5 mi] per hour after extended engine operation with the fault code active.

Conditions for Clearing the Fault Code:
1) Start the engine and let it idle. If, after the engine idles for 10 minutes, the fault code is still not active, the repair has been validated.
2) The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications.

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

Possible Causes:
1) Malfunctioning dosing unit
2) Short circuit to ground in the aftertreatment diesel exhaust fluid dosing unit signal/dosing unit temperature wire.