John Deere Engines SPN2630FMI3 Fault Code: Charge Air Cooler Outlet Temperature Signal Out Of Range High
Also called Charge Air Cooler Outlet Temperature Signal Out of Range High, Engine Shutdown Commanded by Application
Charge Air Cooler Outlet Temperature Signal Out Of Range High · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
SPN 2630 FMI 3 means the ECU is seeing a charge air cooler outlet temperature signal voltage that is out of range high, a value that would correspond to an impossible temperature. The ECU falls back to a default charge air cooler outlet temperature of -1° C (30° F) and tries to keep the engine running within its normal operating envelope. Alarm level is Warning.
Medium severity. This is logged as a Warning-level alarm, not a shutdown code, and the ECU compensates with a default temperature value to keep the engine in its operating envelope. It should still be diagnosed promptly because the ECU is running on an assumed value instead of real charge air data, which can affect performance and emissions control accuracy.
What does John Deere Engines error code SPN2630FMI3 mean?
SPN 2630 FMI 3 is triggered when the charge air cooler outlet temperature sensor signal voltage to the ECU is higher than the sensor's specification allows, or in some descriptions the signal corresponds to a temperature that is not physically possible for that location in the intake system.
The charge air cooler, also called an intercooler, cools compressed air coming from the turbocharger before it enters the engine. The outlet temperature sensor tells the ECU how effective that cooling is so fueling and boost-related strategies stay accurate. When the ECU can't trust this signal, it substitutes a default value of -1° C (30° F) and keeps trying to maintain the engine's normal operating envelope.
This is flagged as a Warning alarm level, meaning the engine keeps running, but the ECU is operating on an assumed charge air temperature rather than a real one until the fault is fixed.
What triggers a John Deere Engines SPN2630FMI3 code?
The code sets whenever the ignition is on and the fault condition is active: the charge air cooler outlet temperature sensor signal voltage read by the ECU exceeds the sensor's high voltage specification, corresponding to a temperature that is not physically possible at that location.
Common causes of SPN2630FMI3
- Bad charge air cooler outlet temperature sensor connector or corroded/damaged terminals at the sensor
- Bad charge air cooler outlet temperature sensor itself
- Bad ECU connector connection or damaged terminals at the ECU
- Open or short in the wiring harness, including pinched or melted wiring or high resistance in the circuit
- Intermittent connection in the harness
- Bad ECU
- Bad or outdated ECU software
How to troubleshoot John Deere Engines SPN2630FMI3: first checks
- Inspect the charge air cooler outlet temperature sensor connector for corrosion, moisture, bent pins, or looseness, and clean or reseat as needed
- Visually trace the wiring harness between the sensor and the ECU looking for pinched, melted, chafed, or heat-damaged sections, especially near the turbo and charge air piping
- Check the ECU connector for damaged or loose terminals and confirm it is fully seated
- Test the sensor and harness for opens or shorts, and check for high resistance in the circuit that could push the signal voltage out of range
- Confirm the ECU software is current, since outdated software is listed as a possible cause
- If wiring and connectors check out, test or swap the charge air cooler outlet temperature sensor itself before condemning the ECU
How the code clears
No separate clearing step is listed beyond repairing the root cause. Since the code is active whenever the ignition is on and the fault condition is present, it should clear on its own once the sensor, connector, or wiring issue is corrected and the ECU sees a valid signal again. Cycling the ignition after the repair is good practice to confirm the fault does not return.
Frequently asked questions
What does SPN 2630 FMI 3 mean on a John Deere engine?
It means the ECU detected a charge air cooler outlet temperature sensor signal voltage that is out of range high, corresponding to a temperature that isn't physically possible. The ECU responds by using a default temperature of -1° C (30° F) and continues trying to maintain normal engine operation.
Can I keep operating the equipment with this code active?
The alarm level is listed as Warning, and the ECU tries to maintain the engine's normal operating envelope using a default value. Many operators can continue working, but the engine is running on an assumed charge air temperature rather than real sensor data, so the fault should be diagnosed as soon as practical.
What is the charge air cooler outlet temperature sensor for?
It measures the temperature of compressed air after it has passed through the charge air cooler (intercooler) and before it enters the engine. This helps the ECU manage fueling and boost-related strategies accurately.
What usually causes this fault?
The most common culprits are a bad sensor, a bad or corroded connector at the sensor or ECU, and wiring problems such as an open, short, high resistance, or pinched/melted harness sections. Outdated or faulty ECU software and a bad ECU are also listed as possible causes.
Do I need to reset the code after repairing it?
No separate clearing step is listed. Once the sensor, connector, or wiring problem is fixed, the fault should stop being active since it is only set whenever the ignition is on and the underlying condition exists.