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SPN 91 FMI 19

Accelerator Pedal Position 1 — Received network data in error.
Data received from another module over the network was flagged as an error or not available.

What the SPN covers: How far the driver is pressing the throttle pedal, sent as a percentage to the engine computer. More on SPN 91.

What FMI 19 usually points to: The problem is usually in the module that sends the data, not the one that logged the code. More on FMI 19.

Severity

HIGH — limit use, diagnose now

The engine may go to idle-only or limp mode. Do not drive in traffic with an unreliable throttle.

Likely causes

  1. Worn or failed pedal position sensor
  2. Corroded pedal connector (common under the cab floor)
  3. Chafed harness
  4. Lost 5 V reference shared with other sensors

Checks & fixes (easiest first)

  1. Check for other network codes and the module that sends this data
  2. Inspect the J1939 backbone and terminating resistors
  3. Watch pedal % on a scan tool while slowly pressing — it should rise smoothly
  4. Inspect the pedal connector for water and corrosion
  5. Check the 5 V reference and ground at the pedal
  6. Check if idle validation switch codes are also present

FAQ

What does SPN 91 FMI 19 mean?

Accelerator Pedal Position 1 — received network data in error. Data received from another module over the network was flagged as an error or not available.

Is SPN 91 FMI 19 serious?

The engine may go to idle-only or limp mode. Do not drive in traffic with an unreliable throttle.

What should I check first for SPN 91 FMI 19?

Check for other network codes and the module that sends this data; Inspect the J1939 backbone and terminating resistors; Watch pedal % on a scan tool while slowly pressing — it should rise smoothly.