PACCAR PX-9 CM2350 (2013-17) Fault Code:2273 PID:411 SPN:411 FMI:3 Exhaust Gas Recirculation Differential Pressure Sensor Circuit – Voltage Above Normal or Shorted to High Source

Reason:
Exhaust Gas Recirculation Valve Delta Pressure Sensor Circuit – Voltage Above Normal or Shorted to High Source. High signal voltage detected at the EGR differential pressure sensor circuit.

Effect:
Possible reduced engine performance.

Circuit Description:
The exhaust gas recirculation (EGR) differential pressure sensor has two ports that sense exhaust pressure. The sensor outputs a voltage which represents the pressure difference between the two ports located across an orifice in the EGR tube. The engine control module (ECM) uses this pressure to determine how much exhaust gas is flowing in the EGR connection tube to the intake manifold. This information is used to control the EGR valve for correct emission levels.The ECM provides a 5 volt supply to the EGR differential pressure sensor on the sensor supply circuit. The ECM also provides a ground on the sensor return circuit. The EGR differential pressure sensor provides a signal to the ECM on the EGR differential pressure sensor signal circuit. This sensor signal voltage changes, based on the differential pressure in the EGR crossover tube.The EGR differential pressure sensor measures the exhaust gas pressure drop across the EGR differential pressure orifice. This pressure drop is used to calculate the amount of EGR flow into the intake manifold.

Component Location:
The EGR differential pressure sensor is mounted on the EGR mass measurement assembly.

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 differential pressure signal voltage was greater than 4.8-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 EGR differential pressure sensor 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:
N/A

Possible Causes:
1) An open return circuit in the engine harness, connectors, or sensor
2) A signal wire shorted to sensor supply or battery voltage
3) A damaged EGR differential pressure sensor