Case IH 19737 – Engine Control Unit (ECU) / Electronic Diesel Control (EDC): Maximum rail pressure exceeded

The fuel pressure inside the common rail has exceeded the maximum safe limit or the specified target value requested by the engine computer. This is a critical fuel system over-pressure event.

• Tier 4b
• Puma
• Magnum
• Steiger

1. 1

   Check the Fuel Metering Valve (M-PROP) on the high-pressure fuel pump for sticking, which can cause an over-pressure condition in the common rail.

2. 2

   Check the Rail Pressure Relief Valve to see if it has blown or popped to protect the system from the sticking metering valve.

3. 3

   Check the Fuel Rail Pressure Sensor to verify that it is not sending intermittent or falsely high raw values to the ECU.

4. 4

   Inspect the high-pressure fuel lines and the metering unit for internal or external leaks.

1. 1

   Monitor rail pressure

   Connect a diagnostic service tool to monitor the actual rail pressure versus the specified (target) rail pressure.

2. 2

   Inspect and replace fuel metering unit

   Inspect the fuel metering unit on the high-pressure pump. If the valve is sticking and causing the pressure spikes, remove and replace the fuel metering unit.

3. 3

   Inspect and replace rail pressure relief valve

   Inspect the rail pressure relief valve. If it has blown due to the over-pressure event, it will stay open and prevent the system from building fuel pressure afterward. If the tractor is struggling to build pressure after this code was logged, replace the pressure relief valve.

4. 4

   Replace fuel filters

   Replace the fuel filters to ensure no debris is causing the metering valve to stick.

5. 5

   Clear codes and test run

   Clear the ECU fault codes and test run the machine to verify that the rail pressure remains within the specified limits.