Deutz-Fahr 157 – ECU: Deviation of Signal During Start or After-Run Above Target Range

The engine control system has detected that the signal from the common rail pressure sensor is outside of the expected or plausible range during the engine's starting or after-run sequences. This indicates an issue with the signal integrity or performance under these conditions, pointing to a potential problem with the sensor itself, its wiring, or the actual fuel pressure it is measuring.

• TCD 2.9
• TCD 3.6
• TCD 4.1
• TCD 6.1
• TCD 7.8
• TD2.9L4
• TCD6.1L6
• TCD2012L42V
• TCD2013L62V
• TCD3.6L4
• 2.2

1. 1

   Use a diagnostic tool (e.g., Deutz SerDia) to read active and stored fault codes, noting the FMI for specific fault details.

2. 2

   Visually inspect the rail pressure sensor wiring harness and connector for damage, corrosion, loose pins, or fluid contamination.

3. 3

   Check for related fault codes regarding the pressure relief valve (PRV) or fuel metering unit (MProp) that might indicate a broader fuel system issue.

4. 4

   Test the sensor's electrical function: verify a steady 5.0V reference supply, check ground continuity (less than 0.5 ohms), and monitor signal voltage (approx. 0.5V engine off, 1.0-1.5V at idle).

5. 5

   Check the fuel system for air in the lines and ensure it is properly bled.

6. 6

   Inspect the Pressure Relief Valve (PRV) for faults or sticking, which can cause pressure issues and premature sensor failure.

1. 1

   Repair wiring and connectors

   Address any issues found with the wiring harness or connectors during the visual inspection. Clear fault codes and re-test to see if the fault returns.

2. 2

   Replace rail pressure sensor

   If electrical tests fail or the sensor is deemed faulty, replace the rail pressure sensor along with its o-ring/seal. If PRV-related codes are present, replace the pressure relief valve at the same time.

3. 3

   Torque sensor

   Install the new rail pressure sensor and tighten it to the manufacturer's specified torque setting of 80 Nm.

4. 4

   Final system check

   Clear all ECU fault codes, start the engine, and monitor live data for the rail pressure sensor to ensure it is reading correctly and the fault does not reappear.