JD-SPN168-FMI1 critical John Deere PowerTech ›

Battery / ECU Power Supply Voltage - Data Valid but Below Normal Operational Range (Most Severe)

The JD-SPN168-FMI1 (John Deere PowerTech) diesel fault code means: Battery / ECU Power Supply Voltage - Data Valid but Below Normal Operational Range (Most Severe). This is a critical severity code.

My Garage →
Keep driving?
No — stop driving
DIY difficulty
intermediate
Estimated cost
$60-$280 wiring/relay, $180-$450 module -- add dealer diagnostic time ($180-$240/hr in 2026)

What Are the Symptoms of JD-SPN168-FMI1?

  • Intermittent code set on load or vibration
  • Relay / actuator not responding as commanded
  • Operator display warning icon

What Causes JD-SPN168-FMI1? (Most Likely First)

  • Corroded weatherpack connector on frame harness Very Likely
  • Failed relay or open fuse on the output circuit Likely
  • Broken wire at actuator strain relief Likely
  • Low battery voltage under crank Possible

Can I Still Drive with JD-SPN168-FMI1?

No — stop driving. JD-SPN168-FMI1 is rated critical severity. Continuing to drive in this state risks further damage — get it looked at before your next trip.

Frequently Asked Questions

What is John Deere fault code SPN 168 FMI 1?

On John Deere PowerTech engines, SPN 168 FMI 1 means: Battery / ECU Power Supply Voltage - Data Valid but Below Normal Operational Range (Most Severe). Critical code -- stop operating until repaired.

Can I keep using my John Deere tractor with SPN 168 FMI 1?

Critical fault -- do not operate; tow or trailer to a dealer. Diagnose with John Deere Service ADVISOR via an EDL v3 / CF3 interface.

How much does it cost to fix John Deere SPN 168 FMI 1?

Repair cost range: $60-$280 wiring/relay, $180-$450 module -- add dealer diagnostic time ($180-$240/hr in 2026). Dealer labor on large tractors runs $180-$240/hr in 2026.

Mechanics Guide Step-by-step diagnosis

How Do You Diagnose JD-SPN168-FMI1?

  1. Confirm system voltage at key-on >12.4V (or 24V on heavy chassis).

  2. Measure circuit resistance end-to-end; compare against Technical Manual (CTM) spec.

  3. Activate the output through Service ADVISOR and watch for expected current draw.

  4. Inspect for rodent damage at the valve-cover pass-through on row-crop tractors.

Sources 1

This page is built from documented references. Verify against your own service info before repair work.

  • SAE J1939-73Application Layer: Diagnostics (defines the SPN/FMI fault-identifier framework)

Which Vehicles Commonly Get JD-SPN168-FMI1?

  • 2015+ John Deere 7R Series (7210R, 7250R, 7290R, 7310R)
  • 2015+ John Deere 9R / 9RT / 9RX Series (9370R-9620R)
  • John Deere S670 / S680 / S690 combines
  • John Deere 544 / 624 / 724 wheel loaders
  • John Deere R4045 / R4060 self-propelled sprayers

Explore More

More John Deere PowerTech codes → Diesel home All diesel codes Heavy-duty Guides

Was this helpful?

Send this to whoever is fixing the truck — your tech, or the person asking what the fault means.