Glow Plug / Grid Heater Indicator - Condition Exists
The JD-SPN1081-FMI31 (John Deere PowerTech) diesel fault code means: Glow Plug / Grid Heater Indicator - Condition Exists. This is a moderate severity code.
Unverified. We could not confirm this code's definition against freely available manufacturer documentation, so treat the meaning, severity and fix guidance on this page as unconfirmed. Check it against the manufacturer's service information for your exact model and serial range before acting on it. This page is kept out of search engines for that reason, and we are working through this family manual by manual.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- intermediate
- Estimated cost
- $60-$280 wiring/relay, $180-$450 module
What Are the Symptoms of JD-SPN1081-FMI31?
- Intermittent code set on load or vibration
- Relay / actuator not responding as commanded
- Operator display warning icon
What Causes JD-SPN1081-FMI31? (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-SPN1081-FMI31?
Yes, but fix soon. JD-SPN1081-FMI31 is rated moderate severity. It is not an immediate stop-driving fault, but it will not clear itself — book the repair rather than ignoring it.
Frequently Asked Questions
What is John Deere fault code SPN 1081 FMI 31?
On John Deere PowerTech engines, SPN 1081 FMI 31 means: Glow Plug / Grid Heater Indicator - Condition Exists. Moderate code -- diagnose soon; continued operation may increase repair scope. Compact-tractor glow plug relay (RE67018 family) is a known wear item; check relay ground stud first.
Can I keep using my John Deere tractor with SPN 1081 FMI 31?
Moderate fault -- you can usually keep working but expect derate if aftertreatment-related. Diagnose with John Deere Service ADVISOR via an EDL v3 / CF3 interface.
How much does it cost to fix John Deere SPN 1081 FMI 31?
Repair cost range: $60-$280 wiring/relay, $180-$450 module. Dealer labor on large tractors runs $180-$240/hr in 2026.
Mechanics Guide Step-by-step diagnosis
How Do You Diagnose JD-SPN1081-FMI31?
Confirm system voltage at key-on >12.4V (or 24V on heavy chassis).
Measure circuit resistance end-to-end; compare against Technical Manual (CTM) spec.
Activate the output through Service ADVISOR and watch for expected current draw.
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-SPN1081-FMI31?
- John Deere 1025R sub-compact utility tractor
- John Deere 2025R / 2038R / 2032R compact utility tractors
- John Deere 3025E / 3032E / 3039R compact utility tractors
- John Deere X500 / X700 / X750 Signature Series lawn tractors
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