John Deere Engines SPN2049FMI9 Fault Code: No CAN Message Received From Source Address 49
Also called CAB Signal Missing, Cab Signal Missing, Engine Shutdown Commanded by Application
No CAN Message Received From Source Address 49 · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
SPN 2049 FMI 9 means the engine ECU is not receiving the a/c clutch status message over CAN from the cab controller, or the message it does receive is not valid. Also logged as DTC 002049.09. When it sets, the ECU defaults fan speed to 1200 rpm.
Medium severity. This code does not shut the engine down on its own, but the ECU forces the cooling fan to a fixed default speed and the air conditioning clutch control is lost over CAN. It should be diagnosed the same shift, especially if fan behavior or cab climate control seems off, since a stuck-fast or stuck-off fan default can affect engine cooling in demanding conditions.
What does John Deere Engines error code SPN2049FMI9 mean?
This code points to a communication failure on the CAN, the Controlled Area Network that links the cab controller to the engine ECU. Normally the cab sends the engine ECU a message telling it the desired air conditioner clutch status. SPN 2049 FMI 9 sets when that message never arrives at the ECU, or arrives but fails validation.
Because the ECU no longer has good information from the cab about a/c clutch demand, it falls back to a default behavior: forcing the cooling fan to run at 1200 rpm instead of following normal fan logic. This is a safe-default response, not a shutdown, but it means the fan will not respond normally to actual cooling or a/c needs until the fault clears.
Some documentation for this code family also lists it as 'No CAN Message Received From Source Address 49' and ties it to general CAN network faults rather than only air conditioning signals, so the underlying issue is really about network communication health between control modules.
Common causes of SPN2049FMI9
- A broken, shorted, or corroded CAN wiring connection between the cab controller and the engine ECU
- A failed or unresponsive cab controller that is not putting the a/c clutch status message on the CAN bus
- General CAN network problems affecting communication from other control units, not limited to the a/c circuit
- A fault in the ECU itself if all other CAN and vehicle-related codes check out clean
How to troubleshoot John Deere Engines SPN2049FMI9: first checks
- Connect a diagnostic tool such as Service ADVISOR or the DST, turn the ignition ON with the engine OFF, and read both active and stored DTCs
- Check specifically for DTC 000639.13 (CAN ERROR); if it is also present, that code's diagnostic procedure takes priority since it points to a broader CAN network fault
- Inspect CAN wiring and connectors between the cab controller and the ECU for corrosion, chafing, loose pins, or damage
- If no other CAN or vehicle-related DTCs are stored or active, the ECU itself is suspected and should be replaced and retested
How the code clears
No separate clearing step is listed beyond the diagnostic procedure. The documented process is to read active and stored DTCs, check for DTC 000639.13 and address it first if present, and if no other CAN or vehicle-related codes are found, replace the ECU and retest to confirm the fault does not return.
Frequently asked questions
What does SPN 2049 FMI 9 mean on a John Deere engine?
It means the engine ECU is not receiving the a/c clutch status message from the cab controller over the CAN network, or the message it receives is invalid. It is also described as CAB Signal Missing or No CAN Message Received From Source Address 49.
Will this code shut down my engine?
The documentation for this specific FMI 9 code does not describe an engine shutdown. Instead, the ECU defaults the cooling fan speed to 1200 rpm as a safe fallback while the CAN signal is missing.
Why is my cooling fan stuck running at a fixed speed?
When the ECU loses the a/c clutch status message over CAN, it cannot calculate the normal fan speed demand, so it defaults to 1200 rpm until the CAN communication issue is resolved.
Do I need a diagnostic tool to fix this?
Yes. The documented procedure requires connecting Service ADVISOR or the DST with the ignition ON and engine OFF to read active and stored DTCs, since the next steps depend on whether other CAN-related codes are also present.
What if DTC 000639.13 also shows up?
If DTC 000639.13 (CAN ERROR) is also active or stored, you should follow that code's own CAN error diagnostic procedure first, since it points to a wider network issue that can also cause SPN 2049 FMI 9.
Does replacing the ECU always fix this code?
Only after ruling out other causes. The documented procedure says to replace the ECU and retest only if no other stored or active CAN or vehicle-related DTCs are found.
Is this the same as a general CAN communication fault?
It's closely related. One version of the documentation describes it broadly as the ECU not receiving a CAN message from another control unit, so while the specific message involved is a/c clutch status, the root cause is often a general CAN network communication problem.