John Deere Error Code ECU 000412.00 — What It Means and How to Fix It
Applies to: All Tier 4 Interim and Tier 4 Final JD engines, 6R Series (6110R-6250R), 7R Series (7210R-7310R), 8R/8RT Series, 9R/9RT/9RX Series, S-Series combines
Reduce engine load. Check the entire cooling system — coolant level, radiator cleanliness, fan operation. The EGR shares the engine cooling circuit.
EGR Temperature High — Engine Power Limited
The Exhaust Gas Recirculation system temperature is above specification. The ECU limits power to protect the engine and emissions system. This is one of the most common and most frustrating codes on Tier 4 Final engines.
Repair difficulty
DIY — Basic toolsRepair time
30 min
Dealer cost
$200-5000
What to check first
- 1
Reduce load and idle for 5 minutes to let the EGR system cool down
- 2
Check the cooling system — coolant level, radiator/cooler stack cleanliness, fan operation. EGR cooling depends on the engine cooling circuit.
- 3
Inspect the EGR cooler for visible coolant weeping or leaks — a cracked EGR cooler is a common failure on high-hour engines
Likely causes
- 1
Engine cooling system issue (blocked radiator, low coolant) affecting EGR cooler— Most likely
DIYThe EGR cooler uses engine coolant. If the cooling system is compromised, EGR temps rise.
- 2
EGR cooler failure (internal crack or blockage)— Possible
ShopCommon on high-hour engines. Coolant weeping from the cooler is the tell-tale sign. Shop replacement.
- 3
EGR valve stuck or carbon-fouled— Possible
ShopCarbon buildup can restrict gas flow and cause temperature spikes. Can sometimes be cleaned.
- 4
EGR temperature sensor fault— Possible
DIYIf the code appeared suddenly and the engine feels fine, the sensor may be faulty.
- 5
Turbocharger issue affecting exhaust gas temperatures— Less common
ShopA failing turbo can raise exhaust temperatures throughout the system.
Parts needed
EGR temperature sensor
OEM: Model-specific$100
Varies by engine model. Verify before ordering.
Search for this part →EGR cooler
OEM: Model-specific$1250
Major component — $500-2,000 depending on model. Confirm diagnosis before ordering.
Search for this part →EGR valve
OEM: Model-specific$650
$300-1,000 depending on model. Often can be cleaned rather than replaced.
Search for this part →
Tools needed
- Standard socket set
- Torque wrench (for cooler/valve work)
- Coolant drain pan
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Pro tip
Keep the entire cooling system in top condition — the EGR cooler is only as effective as the cooling system that feeds it. Also, avoid extended low-load idling — this causes carbon buildup in the EGR valve more quickly than normal operation.