New Holland 3513 – ECM: SCR Catalyst Not Present

The Engine Control Module (ECM) has detected an implausible relationship between the temperatures of the upstream and downstream Selective Catalytic Reduction (SCR) catalyst temperature sensors. During normal operation, the ECM expects a specific temperature increase across the catalyst. When this difference is not observed, the system determines that the SCR catalyst is either physically missing, damaged, or that the temperature sensors are providing inaccurate readings.

• T7
• T8
• Magnum

1. 1

   Visually inspect the SCR catalyst to ensure it is present and has not been tampered with or hollowed out.

2. 2

   Examine the exhaust system for any cracks, leaks, or damage, especially around the SCR catalyst housing.

3. 3

   Inspect the wiring harnesses and connectors for both the upstream and downstream SCR temperature sensors for signs of damage, corrosion, chafing against heat shields, or loose connections.

4. 4

   Using a diagnostic tool, monitor live data from both SCR temperature sensors. With a cold engine, both should read close to ambient temperature. As the engine warms, both should rise, with the downstream sensor showing a higher temperature. Identify any sensor that is stuck on a certain value or does not change.

5. 5

   Test the DEF concentration with a refractometer (should be 32.5%) and check for DEF crystallization in the dosing valve, injector, and throughout the system to rule out blockages.

1. 1

   Repair wiring or replace temperature sensor

   If diagnostic checks reveal a faulty temperature sensor (e.g., open circuit, short circuit, or implausible/stuck reading), replace the affected sensor. Repair any damaged wiring or connectors found during inspection and ensure all connections are clean and secure.

2. 2

   Replace SCR catalyst

   If the SCR catalyst is found to be missing, damaged, or internally melted/clogged (which can result from poor DEF quality or excessive soot), replace the SCR catalyst assembly.

3. 3

   Clear codes and verify system

   After completing repairs, use a diagnostic tool to clear fault code 3513 from the ECM. Perform a drive cycle under various load conditions or run a specific SCR system verification test with the diagnostic tool to allow the ECM to run its self-checks and verify the repair.