John Deere Engines SPN611FMI4 Fault Code: Injector Drive #1 Shorted to Ground
Also called Electronic Injector Wiring Shorted To Ground, Electronic Injector Wiring Shorted to Ground, Electronic Unit Pump Circuit Shorted to Ground, Injector Drive Shorted to Ground, Injector Needle Control Valve Drive Shorted to Ground, Injector Needle Control Valve High Side Drive Shorted to Ground, Injector Shorted to Ground, Injector Wiring Shorted To Ground, Injector Wiring Shorted to Ground
Injector Drive #1 Shorted to Ground · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
SPN 611 FMI 4 means the ECU has detected that electronic injector or electronic unit injector wiring is shorted to ground. Depending on the ECU software version, some control units will stop the engine from running while this code is active, while others allow it to keep running but may cause no-start, rough running, or excessive black smoke.
Critical severity. On some John Deere ECU software revisions, the alarm level for this code is listed as Stop, meaning the ECU will not permit the engine to operate while the code is active. On other ECU versions the engine may still run but with no-start risk, rough running, or excessive black smoke. Because of this stop-engine behavior on some software, treat this as a critical code until you know how your ECU responds.
What does John Deere Engines error code SPN611FMI4 mean?
SPN 611 FMI 4 sets when the engine control unit (ECU) detects that the wiring feeding the electronic injectors or electronic unit injectors is shorted to ground. On 10.5 L and 12.5 L engines this covers electronic unit injectors (EUIs), which combine the injection pump and injector in one unit mounted in the cylinder head. On 8.1 L, 6.8 L, and 4.5 L engines it covers electronic injectors (EIs) fed by a high pressure common rail, using a Two-Way Valve (TWV) in the injector body to control injection timing and amount.
In both designs, power to the injectors is supplied by shared common wires (cylinders 1, 2, 3 on one wire and cylinders 4, 5, 6 on another, or cylinders 1 and 4 versus 2 and 3 on the 4.5 L engine). The ECU controls each individual injector by opening and closing its own ground (low side) circuit. On some ECU designs, the control unit has two internally connected terminals that supply a shared high voltage feed (+90V) to all injectors, with the ECU switching the low side to fire each injector.
This code can be triggered by a short to ground on the shared high side wiring, a short to ground on an individual injector's low side wiring, or by an injector coil itself that is shorted to ground. When this code is active, the ECU generally does not change how it controls the injection system, but the underlying short can cause a no-start condition, rough running, or excessive black smoke. On some ECU software versions, the alarm level is set to Stop, meaning the ECU will not allow the engine to run while the fault is active.
What triggers a John Deere Engines SPN611FMI4 code?
The ECU sets SPN 611 FMI 4 when it detects that injector wiring is shorted to ground. This can be a short to ground on the shared injector high side (+90V) supply wiring, a short to ground on an individual injector's low side (ground) wiring, or an injector coil internally shorted to ground. Depending on ECU software revision, this DTC may display while the engine is cranking, running, or during Harness Diagnostic Mode with the fault condition active. On some ECU software versions, the code may only be displayed during a Harness Diagnostic Mode test run in Service ADVISOR.
Common causes of SPN611FMI4
- Bad terminals or connector at the EUI or EI harness connector
- Short in the harness between the ECU and the EUI or EI harness, or a short within the injector harness itself
- Bad terminals or connector at the ECU
- Bad EUI or EI harness (damaged wiring)
- Bad ECU connector connection
- Bad ECU
- Bad EUI or EI (injector shorted internally to ground)
- Intermittent wiring problem in the harness
- Bad or outdated ECU software
How to troubleshoot John Deere Engines SPN611FMI4: first checks
- With the key off, visually inspect the 60-way and 48-way ECU connectors, the EUI or EI harness connector, and any connectors in between for dirty, damaged, or poorly positioned terminals.
- Without disconnecting components, check the wiring itself along its length for chafing, pinching, or damage that could let a wire touch ground.
- Look closely at terminal contamination or corrosion at the ECU end and at the injector harness connector end, since bad terminal contact at either end is a listed cause.
- Check for an intermittent wiring problem by gently flexing or moving harness sections near the ECU and injectors while watching for the fault to come and go, if your diagnostic tool allows live monitoring.
- Confirm the ECU software revision is current, since outdated ECU software is a listed possible cause on some engine platforms.
- If wiring and connectors check out, the individual injector coils and the ECU itself become suspects and should be tested per the injector and ECU test procedures for your engine.
How the code clears
No separate clearing step is listed. Because on some ECU software the alarm level is Stop and the engine will not run while this code is active, the fault must be found and repaired (correcting the short to ground in the harness, connector, injector, or ECU) before normal operation can resume. Once the underlying short is corrected, the code should stop being active; always verify with a health check or by cycling the key and rechecking with your diagnostic tool.
Frequently asked questions
What does SPN 611 FMI 4 mean on a John Deere engine?
It means the ECU has detected that electronic injector or electronic unit injector wiring is shorted to ground. This can be on the shared high side supply wiring, on an individual injector's ground wiring, or inside an injector coil itself.
Will my John Deere engine still run with this code active?
It depends on the ECU software. On some engines the ECU does not change how it controls the system, so the engine may run but rough, may not start, or may smoke excessively black. On other ECU software revisions, the alarm level is set to Stop and the ECU will not permit the engine to run at all while the code is active.
What is an EUI versus an EI on John Deere engines?
EUI stands for Electronic Unit Injector, used on 10.5 L and 12.5 L engines, where the injection pump and injector are combined in one unit in the cylinder head. EI stands for Electronic Injector, used on 8.1 L, 6.8 L, and 4.5 L engines, which receive fuel from a high pressure common rail and use a Two-Way Valve (TWV) to control injection.
Can a bad connector alone cause SPN 611 FMI 4?
Yes. Bad terminals or connectors at the ECU or at the injector harness connector are listed possible causes, along with shorts in the harness wiring, a bad harness, a bad injector, or a bad ECU.
Where should I start diagnosing SPN 611 FMI 4?
Start with a visual inspection of the ECU connectors (60-way and 48-way where applicable), the EUI or EI harness connector, and any connectors in between, looking for dirty, damaged, or poorly seated terminals and for damaged wiring before moving on to injector or ECU testing.
Is this code related to a specific injector cylinder?
Not directly by cylinder number. Power is supplied to groups of injectors (cylinders 1, 2, 3 on one common wire and 4, 5, 6 on another, or 1 and 4 versus 2 and 3 on 4.5 L engines), so a short can affect one injector or an entire group depending on where the short occurs.
Does updating ECU software fix SPN 611 FMI 4?
Outdated or bad ECU software is listed as one possible cause on some engine platforms, so checking for and applying current ECU software is a reasonable step if wiring, connectors, and injectors all check out fine.