What is P0503 fault code? What is the explanation for the Vehicle Speed Sensor “A” Intermittent fault? How can I fix the P0503 fault code What are the causes and symptoms for the P0503 fault code
What is the P0503 Fault code? What does it signify?
P0503 means that the powertrain control module, (PCM), detected an intermittent or inconsistent voltage signal coming from the vehicle speed sensor. This voltage signal may be inconsistent or intermittent. It can also be excessively high, low, irregular, unreasonable, mismatched with input data. VSS systems that have more than one vehicle speed sensor usually have the “A” label in their code description.
The primary purpose of the speed sensor’s speed sensor is to inform the driver about the vehicle’s speed. However, other control modules and systems can also use this data. Some vehicles have adaptive power steering systems that use the speed data to adjust steering sensitivity according to vehicle speed. When calculating the best braking strategy, the ABS control module compares this data.
The vehicle’s current speed can also affect systems like cruise control, shift strategies, and engine drivability settings. The vehicle’s driveability and fuel consumption could be affected if the PCM receives the wrong speed sensor input data.
Most applications have one speed sensor. It is located near the transmission output shaft. But some applications may have multiple speed sensors at different locations. Sometimes, one or more wheels speed sensors can double as vehicle speed sensors. However, this is very rare. This is a common scenario and applies mostly to all-wheel drive or high-end vehicle applications.
The majority of vehicle speed sensors, however, are electromagnetic and work with a reluctor band. When the sensor is in contact with the reluctor band’s teeth, it creates an electromagnetic field. These magnetic fields are converted by the sensor into an electrical signal that is transmitted to the computer. The PCM converts the signals into an electrical signal that corresponds to road speed. It then notifies the driver using miles or kilometers. The speedometer will reflect the value. Some sensors also do not include a relay ring. Two interlocking gears drive the speed sensor element in these applications.
Vehicle drivability can be adversely affected by an inaccurate, irregular, unreasonable, or erratic voltage signal coming from the vehicle speed sensor. The PCM will set fault code P0503 if it detects a slight deviation in the vehicle’s speed from the speed sensor. An instrument cluster warning light will also be lit.
P0503 fault codes can be found on many vehicles, including, but not limited, to Proton and Renault models as well as Duster, BMWs, Minis, Fords, Fiats, Cadillacs, Lexus cars, Porsches, Peugeots, and Volvos.
What causes the P0503 Fault code?
Below are some reasons to set fault code P0503:
- – Vehicle speed sensor that is dirty or defective
- – Sensors for speed of dirty or defective wheels
- – Broken, burnt, disconnected, or corroded wires and/or connectors for speed sensors
- Defective hubs
- – Defective or damaged reluctor wheels
- – Tire sizes not in standard affect the calibration of other control modules and the PCM.
- – Issues with PCM modules or other modules
What are the Symptoms of the P0503 Fault Code
The following symptoms may be experienced by anyone who has a vehicle that is coded P0503.
- – Illumination for the check engine light
- – ABS and Traction control system warning lights are on
- Fluctuations of speedometer up or down
- – Speedometer is showing an incorrect speed compared to the vehicle
- – Odometer not showing or working correctly
- – Deactivation and activation of the cruise control system
- – Disabled ABS/traction control systems
- – Reduced engine speed
- – Autotransmission shifts can be hard and unpredictable
- PCM can limit vehicle speed through failsafe mode
How do I fix the P0503 fault code?
Some repairs that could resolve the P0503 fault code are:
- – Replacing faulty speed sensors
- – Clean all speed sensor
- – Replace or repair damaged, corroded, or shorted components, connectors, cables, and other parts to speed sensors
- – Replacing a damaged hub on a wheel
- – Cleaning, checking and replacing the reluctor rings
- – Checking the dimensions of the wheel, correcting them if necessary or defining them according to the PCM
- – Replacing damaged hubs
- – Reprogramming or replacement for a defective PCM
How serious is the Fault Code P0503?
A P0503 code should always be considered serious and taken seriously. It can lead to ABS and driveability problems. This code means that VSS may not be working properly. Driving with this code for too long can result in erratic gear changes, transmission damage, and even loss of control. Safety systems like ABS and traction control may also be disabled.
