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SPN 629 FMI 12

Controller #1 — Bad intelligent device or component.
A smart sensor, actuator, or module has reported an internal failure or is not responding correctly.

What the SPN covers: The engine controller itself has detected an internal problem. More on SPN 629.

What FMI 12 usually points to: Internal failure of the device itself; sometimes a power/ground problem makes a good device look bad. More on FMI 12.

Severity

HIGH — limit use, diagnose now

Can range from minor to no-start. Check power and grounds before blaming the ECM.

Likely causes

  1. Internal ECM fault
  2. Corrupted or interrupted programming
  3. Poor power or ground supply
  4. Water intrusion

Checks & fixes (easiest first)

  1. Check ECM power and ground
  2. Check for software updates or a failed reflash
  3. Inspect connectors for water

FAQ

What does SPN 629 FMI 12 mean?

Controller #1 — bad intelligent device or component. A smart sensor, actuator, or module has reported an internal failure or is not responding correctly.

Is SPN 629 FMI 12 serious?

Can range from minor to no-start. Check power and grounds before blaming the ECM.

What should I check first for SPN 629 FMI 12?

Check ECM power and ground; Check for software updates or a failed reflash; Inspect connectors for water.