Aftertreatment Fuel Pressure Sensor Circuit – Voltage Above Normal or Shorted to High Source
Overview
| CODE | REASON | EFFECT |
| Fault Code: 1927 PID: S332 SPN: 3480 FMI: 3/3 LAMP: Amber SRT: |
High signal voltage detected at the aftertreatment fuel pressure sensor circuit.
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Possible reduced engine performance.
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Aftertreatment Fuel Pressure Sensor Circuit
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Circuit Description
The aftertreatment fuel pressure sensor is used to monitor the fuel pressure into the aftertreatment system. The engine control module (ECM) supplies the aftertreatment fuel pressure sensor a 5 volt reference voltage. When the fuel pressure is low, the sensor signal voltage is low. When the fuel pressure is high, the sensor signal voltage is near the 5 volt reference voltage. The ECM monitors the aftertreatment fuel pressure signal circuit voltage to calculate the pressure of the fuel within the aftertreatment system.
Component Location
The aftertreatment fuel injector is installed in the exhaust system in the turbocharger adapter pipe. The aftertreatment fuel pressure sensor and aftertreatment fuel shutoff valve are installed in the shutoff valve manifold. The aftertreatment purge air actuator is located above the shutoff valve manifold.
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 aftertreatment fuel pressure signal voltage was out of range high.
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.
Active regeneration of the aftertreatment diesel particulate filter will be disabled unitl the next key cycle.
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
- To validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.
- The fault code status displayed by the recommended Cummins electronic service tool or equivalent will change to INACTIVE immediately after the diagnostic runs and passes.
- The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
- 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.
Possible causes of this fault code include:
Open return circuit in the engine harness, connector, sensor
Signal wire shorted to sensor supply or battery voltage
A shorted sensor.
Troubleshooting Summary
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the aftertreatment fuel pressure sensor from the engine wiring harness.
Action
- Inspect the pins and connectors for damage.
- Turn keyswitch ON.
- Connect the recommended Cummins electronic service tool or equivalent.
- Wait 30 seconds before checking the circuit response.
- Use the recommended Cummins electronic service tool or equivalent to read the fault codes.
Specification
- A malfunctioning aftertreatment fuel pressure sensor has been detected if the following fault code became active with the sensor disconnected: 1928
Linked Solutions
- None
Repair
- Replace aftertreatment fuel pressure sensor.
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.
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the engine wiring harness connector from the ECM.
Action
- Inspect the pins and connectors for damage.
- Turn keyswitch ON.
- Connect the recommended Cummins electronic service tool or equivalent.
- Wait 30 seconds before checking the circuit response.
- Use the recommended Cummins electronic service tool or equivalent to read the fault codes.
Specification
- A malfunctioning ECM has been detected if the following fault code does not become active with the engine wiring harness disconnected: 1928
- A malfunctioning engine wiring harness has been detected if the following fault code became active with the engine wiring harness disconnected: 1928
Linked Solutions
- None
Repair
Repair or replace only the components that were found to be out of specification.
- Replace the ECM.
- Repair or replace the engine wiring harness.
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.