John Deere 5246.31 – ECU: SCR Operator Final Derate Notification / Engine Derate Countdown Active

This is an informational fault code rather than a component failure code. It notifies the operator that the machine has reached its final engine derate stage. The engine control system intentionally limits engine power, speed, or performance to ensure emissions compliance because a prior Selective Catalytic Reduction (SCR), Diesel Exhaust Fluid (DEF), or Diesel Oxidation Catalyst (DOC) issue was ignored or not repaired within the allotted countdown time.

• 5085E
• 5090E
• 5090EL
• 5100E
• 5090M
• 5100M
• 5100MH
• 5100ML
• 5115M
• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 8R / 8RT / 8RX Series Tractors
• 8245R
• 8400R
• 9RT Series Tractors
• 9470RT
• 9520RT
• 9570RT
• S-Series Combines
• S660
• S670
• S680
• S690
• S700
• S780
• S790
• M and R Series Tractors
• 6105M

1. 1

   Scan for active root-cause codes using a diagnostic scanner to find accompanying emissions faults (e.g., DEF dosing unit faults, DOC efficiency codes, or NOx sensor codes).

2. 2

   Check DEF fluid level and test quality with a refractometer to ensure 32.5% urea concentration without water or diesel contamination.

3. 3

   Visually inspect the SCR/DOC exhaust system, DEF dosing pump, and injector lines for leaks, physical damage, or excessive soot buildup/blockages.

1. 1

   Resolve the Underlying Fault

   Diagnose and repair the specific component that triggered the initial emissions countdown (e.g., replace a failed NOx sensor, replace a clogged DEF dosing pump, or clean a restricted DOC).

2. 2

   Refill DEF

   If the derate was caused by running out of fluid or using poor-quality fluid, drain the tank and refill it with fresh, high-quality DEF.

3. 3

   Perform System Tests

   Depending on the root cause, you may need to run a DEF dosing system test or force a stationary exhaust regeneration to verify the SCR system is functioning normally again.

4. 4

   Reset the ECU

   Once the mechanical repair is complete, the derate will not lift on its own. You must use a diagnostic tool (like John Deere Service ADVISOR) to clear the fault codes and reset the ECU. This will remove the 005246.31 code and restore full engine power.