Case IH 3545 – Engine Control Unit (ECU) / Engine Controller: Info: SCR Dosing Valve Overheat Protection - Torque Limitation Level2 for SCR Protection active.

The Engine Control Unit (ECU) has received a CAN message from the Dosing Control Unit (DCU) indicating that the SCR (Selective Catalytic Reduction) dosing module is not being cooled sufficiently. Because of this abnormal overheating condition, the ECU forces a Level 2 torque limitation (derate) to protect the SCR system. Additional fault codes may be generated once the engine torque demand reaches 60% of maximum engine torque.

• Case IH Magnum 235 – 340 (Series 4)
• Case STX Steiger tractors (350 to 600 horsepower)
• Various Case IH Puma, Maxxum, and Optum models equipped with DEF systems

1. 1

   Inspect the coolant lines running to the DEF dosing valve for blockages, kinks, or pinched hoses that would restrict coolant flow.

2. 2

   Verify DEF tank and heater hose routing. Ensure the DEF heater line with the 'red' band is correctly connected to the top tube running to the front part of the engine head to prevent continuous hot water circulation.

3. 3

   Inspect the SCR dosing valve itself for physical damage or signs of severe heat stress.

1. 1

   Correct Coolant Flow

   If the coolant lines are kinked, blocked, or routed incorrectly, reroute or clear the lines to restore proper coolant flow to the dosing module.

2. 2

   Replace the Valve (if damaged)

   If the hoses were connected wrong or coolant flow was restricted for an extended period, the SCR dosing valve is likely damaged from the heat and must be replaced. Disconnect the battery. Disconnect the electrical harness, DEF lines, and coolant lines from the SCR dosing valve. Remove the mounting hardware and remove the old valve. Install the new SCR dosing valve and reconnect all lines and harnesses.

3. 3

   Clear Codes

   Once the repair is complete and proper cooling is restored, use a diagnostic tool to clear the fault code. The ECU will disable the torque derate once the system registers normal temperatures.