Home › Codes › SPN 111 › FMI 1

SPN 111 FMI 1

Coolant Level — Value too low (most severe).
The reading is valid but far below the normal operating range, at the most serious 'too low' level.

What the SPN covers: Coolant level in the expansion tank or radiator, from a level probe or switch. More on SPN 111.

What FMI 1 usually points to: A real under-condition such as very low oil pressure or low fuel pressure, or a sensor that has drifted low. More on FMI 1.

Severity

HIGH — limit use, diagnose now

Low coolant can lead to overheating and head damage. Top off and find the leak before working hard.

Likely causes

  1. Coolant leak (hoses, radiator, water pump, EGR cooler)
  2. Coolant level sensor dirty or failed
  3. Wiring fault

Checks & fixes (easiest first)

  1. Check actual level when cold
  2. Look for external leaks and white exhaust smoke
  3. Clean or test the level probe
  4. Pressure-test the cooling system

FAQ

What does SPN 111 FMI 1 mean?

Coolant Level — value too low (most severe). The reading is valid but far below the normal operating range, at the most serious 'too low' level.

Is SPN 111 FMI 1 serious?

Low coolant can lead to overheating and head damage. Top off and find the leak before working hard.

What should I check first for SPN 111 FMI 1?

Check actual level when cold; Look for external leaks and white exhaust smoke; Clean or test the level probe.