Case IH 19673 – Engine ECU / VCM: Turbine downstream pressure is too low.

This code indicates that the exhaust gas pressure measured immediately downstream of the turbocharger turbine is lower than the engine control system's expected or modeled physical limit for the current operating conditions. This typically points to an exhaust leak between the turbocharger and the aftertreatment system, a drifted/failed sensor, or a blockage/wiring issue.

• Tier 4b
• Case 580N
• Case 580SN
• Case 580SN WT
• Case 590SN

1. 1

   Visual Exhaust Inspection: Check the exhaust piping between the turbocharger turbine outlet and the SCR/DOC aftertreatment system. Look for soot trails, loose V-band clamps, or cracked pipes that would cause a loss of exhaust pressure.

2. 2

   Sensor Port Inspection: Check the turbine downstream pressure sensor's connecting tube/port for severe soot buildup or carbon blockages that could restrict the pressure signal.

3. 3

   Wiring & Circuit Check: Inspect the sensor's wiring harness and connector for chafing, corrosion, or loose pins.

4. 4

   Static Pressure Plausibility Check: Using a diagnostic scan tool, monitor the turbine downstream pressure sensor with the engine OFF (Key On, Engine Off). The reading should match the ambient atmospheric pressure. If it reads significantly higher or lower, the sensor has drifted and is faulty.

1. 1

   Cool Down

   Ensure the machine is turned off and the exhaust system has completely cooled to prevent burns.

2. 2

   Locate the Sensor

   Locate the turbine downstream pressure sensor, which is mounted on the exhaust piping just after the turbocharger.

3. 3

   Fix Exhaust Leaks (If Applicable)

   If your visual inspection revealed soot trails or a blown exhaust gasket, loosen the affected V-band clamp or flange, replace the gasket/seal, and re-torque the clamp to factory specifications.

4. 4

   Remove and Clean

   Disconnect the electrical harness from the pressure sensor. Unthread the sensor from its port. Carefully clean out any carbon/soot buildup in the port using a pick or appropriate solvent.

5. 5

   Replace the Sensor

   If no exhaust leaks were found and the sensor failed the static pressure diagnostic check, install a new turbine downstream pressure sensor.

6. 6

   Clear and Verify

   Reconnect the wiring harness. Use a diagnostic tool to clear fault code 19673. Start the engine and run it under load to ensure the exhaust pressure registers correctly and the code does not return.