PACCAR PX-9 CM2350 (2013-17) Fault Code:2376 PID:412 SPN:412 FMI:4 Exhaust Gas Recirculation Temperature Sensor Circuit – Voltage Below Normal or Shorted to Low Source

Reason:
Exhaust Gas Recirculation Temperature Sensor Circuit – Voltage Below Normal or Shorted to Low Source. Low signal voltage detected at EGR temperature circuit

Effect:
Possible reduced engine performance.

Circuit Description:
The exhaust gas recirculation (EGR) temperature sensor is a variable resistor sensor and is used to measure the temperature of the EGR gas flow after it exits the EGR cooler. The engine control module (ECM) supplies 5 volts to the EGR temperature signal circuit. The ECM monitors the change in voltage caused by changes in the resistance of the sensor to determine the EGR flow temperature.

The EGR temperature value is used by the ECM for the engine protection system and engine emissions control.

Component Location:
The EGR temperature sensor is located on the EGR connection tube between the EGR cooler and the air intake connection.

Conditions for Running the Diagnostics:
This diagnostic runs continuously when the keyswitch is in the ON position or when the engine is running.

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected the EGR temperature signal voltage was less than 0.05-VDC for more than 8 seconds.

Action Taken When the Fault Code is Active:
1) The ECM illuminates the amber CHECK ENGINE lamp and/or the Malfunction Indicator Lamp (MIL) immediately when the diagnostic runs and fails.
2) A default value for the exhaust gas recirculation temperature reading is used.
3) Diesel exhaust fluid injection into the aftertreatment system is disabled.
4) Active and stationary regeneration of the diesel particulate filter will be disabled.
5) Exhaust Gas Recirculation (EGR) valve operation will be disabled.
6) 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:
1) To validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.
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) 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.
5) 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:
The EGR temperature sensor shares return wires in the engine harness with other sensors. An open return can cause multiple fault codes to be active.

Possible Causes:
1) A signal shorted to ground in the harness
2) A signal shorted to return or ground in the sensor