SPN 91 FMI 14 – 2-Channel Accelerator Pedal Not Learned Fault Code (Symptoms, Causes & Fix)

Mar 15, 2026

The SPN 91 FMI 14 fault code indicates a '2-Channel Accelerator Pedal Not Learned' condition in a diesel engine. This diagnostic trouble code (DTC) is triggered when the Engine Control Module (ECM) detects that the accelerator pedal position sensor has not been properly calibrated. This fault can affect the throttle control system's ability to accurately interpret driver input.

What SPN 91 FMI 14 Means

When the SPN 91 FMI 14 fault code is active, it signifies that the ECM has identified an issue with the learning process of the accelerator pedal position sensor. The sensor is responsible for communicating the driver's throttle input to the ECM. If the sensor is not calibrated correctly, the ECM cannot accurately determine the pedal position, potentially leading to throttle response issues.

Common Causes of This Fault Code

Accelerator pedal position sensor not calibrated
Faulty accelerator pedal position sensor
Wiring harness issues such as open circuits or short circuits
ECM software not updated or corrupted

Symptoms Drivers May Notice

Drivers may experience a lack of throttle response or inconsistent acceleration when the SPN 91 FMI 14 fault code is present. In some cases, the engine may enter a reduced power mode, limiting the vehicle's performance.

How Technicians Diagnose This Fault

Technicians begin diagnosing the SPN 91 FMI 14 fault by performing a visual inspection of the accelerator pedal position sensor and its wiring harness. They check for physical damage, corrosion, or loose connections. Next, they use a multimeter to test the continuity and resistance of the wiring harness. Voltage reference testing is conducted to ensure the sensor is receiving the correct power supply. Using OEM diagnostic software, technicians perform a calibration procedure for the accelerator pedal position sensor. Finally, they verify the ECM software version and update it if necessary.

Common Misdiagnosis

One common misdiagnosis is replacing the accelerator pedal position sensor without attempting calibration first. Technicians may also mistakenly attribute the issue to a mechanical problem with the pedal assembly or overlook necessary software updates for the ECM.

Can You Keep Driving?

While it may be possible to continue driving with the SPN 91 FMI 14 fault code active, it is not advisable. The fault can lead to unpredictable throttle response and may cause the engine to enter a derate mode, reducing power output. Addressing the issue promptly is recommended to avoid further complications.

Mechanic's Diagnostic Tip

Before replacing any components, always perform a thorough calibration of the accelerator pedal position sensor using the appropriate diagnostic software. This step can often resolve the issue without the need for part replacement.

Frequently Asked Questions

Q: What tools are needed to diagnose SPN 91 FMI 14?
A: A multimeter and OEM diagnostic software are essential for diagnosing this fault code.

Q: Can a software update fix SPN 91 FMI 14?
A: Yes, if the ECM software is outdated or corrupted, updating it can resolve the fault.

Q: Is it necessary to replace the accelerator pedal position sensor?
A: Not always. Calibration and wiring checks should be performed first to determine if replacement is necessary.