John Deere Engines SPN2797FMI6 Fault Code: Injector High Voltage Supply #1 Circuit Has Low Resistance
Also called Engine Shutdown Commanded by Application, Injector High Voltage Supply Circuit Has Low Resistance
Injector High Voltage Supply #1 Circuit Has Low Resistance · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
SPN 2797 FMI 6 means the ECU has detected an internal problem with the injector high voltage supply circuit, described in some ECU versions as the injector high voltage supply #1 circuit. The ECU sets this as a Warning level alarm, tries to maintain proper operating conditions, and on most engines derates the engine, closes the EGR valve, and stops injection to the injectors sharing that high voltage driver. The engine may not run with this fault active, and the ECU commands an engine stop after two hours of continuous operation with the fault present.
High severity. This is flagged as a Warning level alarm by the ECU, but the control unit response is severe: it can derate the engine, close the EGR valve, stop fuel delivery to affected cylinders, and force a shutdown after two hours of continuous active fault time. Treat it as a stop-soon condition rather than something to run through a shift.
What does John Deere Engines error code SPN2797FMI6 mean?
: SPN 2797 FMI 6 points to the electronic control unit finding an internal problem with the circuit that supplies high voltage to the fuel injectors. On four cylinder engines, injectors #1 and #4 share one common high voltage driver from the ECU. On three cylinder engines, injectors #1, #2, and #3 share one common high voltage driver. The ECU separately switches the low side, or ground, to control each individual injector, so the high voltage supply side and the ground side are handled differently inside the ECU.
This circuit problem is significant because if the high voltage driver has low resistance internally, the ECU can no longer reliably fire the injectors it feeds. Rather than let injectors fire unpredictably, the ECU takes protective action: it tries to hold the engine at proper operating conditions where possible, but it will derate power, shut the EGR valve, and stop commanding injection on the affected cylinders. In many cases the engine simply will not run at all while this fault is active.
What triggers a John Deere Engines SPN2797FMI6 code?
The DTC is set when the ignition is on and the engine is running, cranking, or already running, and the fault condition is active at that time. No separate voltage, temperature, or resistance threshold value is listed for when the ECU decides the circuit has low resistance.
Common causes of SPN2797FMI6
- Bad ECU software
- Bad ECU (the injector high voltage supply driver inside the control unit has failed or has developed low internal resistance)
How to troubleshoot John Deere Engines SPN2797FMI6: first checks
- Confirm exactly which DTC and cylinder callout is active, since the description can appear as injector high voltage supply circuit or as injector high voltage supply #1 circuit depending on the ECU software version.
- Check whether the engine will start and run at all with the fault active. On some versions, injection to the affected cylinders (injectors #1 and #4 on four cylinder engines, or #1, #2, and #3 on three cylinder engines) is stopped by the ECU, which can prevent the engine from running.
- Note how long the fault has been continuously active. The ECU commands an engine stop after two hours of continuous operation with the fault present, so a machine that suddenly shuts down after running for a while with a derate and closed EGR may be approaching that limit.
- Look for other symptoms tied to the ECU response: engine derate, EGR valve stuck or commanded closed, and rough running or a cylinder misfire pattern consistent with the affected injectors not firing.
- Because the listed causes point to the ECU itself, plan for ECU software verification and ECU diagnostic checks rather than spending time on external wiring, since no wiring or connector cause is listed for this specific fault.
How the code clears
No separate reset or clearing procedure is listed for this code. The diagnostic material only identifies the DTC, the ECU's automatic response, and the two possible causes (bad ECU software or a bad ECU). Once the underlying software or hardware issue is corrected, the fault would be expected to clear on its own as the ECU stops detecting the internal circuit problem, but no manual clear or reset steps are documented.
Frequently asked questions
What does SPN 2797 FMI 6 mean on a John Deere engine?
It means the engine control unit has detected an internal problem with the injector high voltage supply circuit, sometimes specifically called the injector high voltage supply #1 circuit. This is the circuit that provides high voltage to fire the fuel injectors.
Will the engine still run with this code active?
It might not. The ECU can stop commanding injection to the injectors that share the affected high voltage driver (injectors #1 and #4 on four cylinder engines, or #1, #2, and #3 on three cylinder engines), and in many cases the engine will not run at all while the fault is active.
Why does the engine shut down after running for a while with this fault?
The ECU is programmed to command an engine stop after two hours of continuous operation with SPN 2797 FMI 6 active, even though the alarm level is only a Warning.
What causes SPN 2797 FMI 6?
Only two causes are identified: bad ECU software or a bad ECU. There is no listed wiring, connector, or injector hardware cause outside the control unit itself.
Does this code affect emissions components?
Yes. As part of its response, the ECU commands the EGR valve fully closed while this fault is active, in addition to derating the engine.
Is SPN 2797 FMI 6 the same on three cylinder and four cylinder engines?
The underlying problem is the same internal high voltage supply circuit issue, but the affected injectors differ: four cylinder engines share injectors #1 and #4 on one driver, while three cylinder engines share injectors #1, #2, and #3 on one driver.
Can I clear this code myself?
No separate reset or clearing procedure is listed for this code. Repair generally involves addressing the ECU software or replacing the ECU, since those are the only two documented causes.