Speedometer Circuit Malfunction
2014-2014 Lincoln MKX 3.7L V6
The 2014 Lincoln MKX is equipped with a 3.7L V6 engine. Below you'll find detailed b0401 diagnostic code information including labor time estimates, cost ranges, and technician notes specific to this engine configuration.
Description
The speedometer gauge is not functioning or is displaying incorrect speed readings.
Symptoms
- Speedometer reads zero while driving
- Speedometer reads erratically
- Speedometer needle bouncing
- Cruise control may not work
Common Causes
- Faulty vehicle speed sensor
- Instrument cluster stepper motor failure
- Cluster circuit board fault
- Speed signal wiring issue
Diagnostic Steps
- Check speed sensor signal with scan tool
- Compare GPS speed to speedometer
- Test cluster stepper motor
- Check speed sensor wiring
- Scan for related speed sensor codes
Repair Notes
Replace speed sensor or instrument cluster stepper motor. If cluster board is faulty, replace or repair cluster.
Related Codes
Other Body Codes
- B0001Driver Frontal Stage 1 Deployment Control
- B0001Driver Frontal Stage 1 Deployment Control
- B0002Driver Frontal Stage 2 Deployment Control
- B0002Driver Frontal Stage 2 Deployment Control
- B0003Passenger Frontal Stage 1 Deployment Control
- B0003Passenger Frontal Stage 1 Deployment Control
- B0004Passenger Frontal Stage 2 Deployment Control
- B0004Passenger Frontal Stage 2 Deployment Control
- B0005Driver Knee Airbag Deployment Circuit
- B0005Driver Knee Airbag Deployment Circuit
B0401 on Other Vehicles
Lincoln Aviator
2003-2003 4.6L V8 DOHC
Lincoln Aviator
2004-2004 4.6L V8 DOHC
Lincoln Aviator
2005-2005 4.6L V8 DOHC
Lincoln Aviator
2020-2020 3.0L Twin-Turbo V6
Lincoln Aviator
2020-2020 3.0L V6 Twin Turbo
Lincoln Aviator
2020-2020 3.0L V6 Twin Turbo Hybrid
Lincoln Aviator
2021-2021 3.0L Twin-Turbo V6
Lincoln Aviator
2021-2021 3.0L V6 Twin Turbo
Common Questions
What does code B0401 mean on a 2014-2014 Lincoln MKX?
B0401 stands for "Speedometer Circuit Malfunction". The speedometer gauge is not functioning or is displaying incorrect speed readings.
What are the symptoms of B0401 on a Lincoln MKX?
Common symptoms of B0401 include: Speedometer reads zero while driving, Speedometer reads erratically, Speedometer needle bouncing, Cruise control may not work.
What causes B0401 on a 2014-2014 Lincoln MKX?
Common causes of B0401 include: Faulty vehicle speed sensor, Instrument cluster stepper motor failure, Cluster circuit board fault, Speed signal wiring issue.
Last updated: March 2026