DTC P0503 - Vehicle Speed Sensor A Intermittent/Erratic/High

WARNING: This page does not describe the selected car, but rather 31 other vehicles, including the 2018 Lincoln Navigator, 2018 Lincoln MKZ, 2018 Lincoln MKX, 2018 Lincoln MKT, and 2018 Lincoln MKC. However, it is still accessible from the selected car via links, so may be relevant.

P0503 - VEHICLE SPEED SENSOR A INTERMITTENT/ERRATIC/HIGH

Description:	This DTC sets when an incorrect or noisy VSS signal is detected. Vehicle speed data is received from either the VSS or the anti-lock brake system (ABS) module.
Possible Causes:	Noisy VSS input signal from radio frequency interference or electromagnetic interference external sources, such as ignition components or the charging circuit Damaged VSS or driven gears Damaged VSS wiring harness or connectors Concern in the modules or circuits connected to the VSS circuit Aftermarket accessories
Diagnostic Aids:	Monitor the VSS PID while driving the vehicle, and check for intermittent vehicle speed indication. Verify the ignition and charging systems are functioning correctly.
Application	Key On Engine Off	Key On Engine Running	Continuous Memory
EcoSport, F-650/F-750, F-Series Super Duty, Fiesta, Fusion, KA, Motorhome/Stripped Chassis/Step Van, Ranger	GO to PINPOINT TEST DF .
Manual Transmission	GO to PINPOINT TEST DP .
All others	The PCM uses information from the ABS module and the transmission control module (TCM) to calculate vehicle speed. Check these modules for DTCs.