B1003 Citroen Auto Trouble Code
B1003 Citroen OBD2 reports a sensor fault, replacement of the sensor is unlikely to resolve the underlying problem. The fault is most likely to be caused by the systems that the sensor is monitoring, but might even be caused by the wiring to the sensor itself.
Accelerator Pedal Position Sensor 1 Circuit Low and P2127 - Accelerator Pedal Position Sensor 2 Circuit Low would lead you to suspect a defective accelerator pedal position sensor.
B1003 Citroen Possible Solution:
Vehicle Speed Sensor (VSS) Out of Self Test Range Indicates the VSS input signal is out of Self Test range. If the PCM detects a VSS input signal any time during Self Test, a DTC P1501 will be set and the test will abort. Noisy VSS input signal from Radio Frequency Interference/ Electro-Magnetic Interference (RFI/EMI) external sources such as ignition wires, charging circuit or after market equipment. Check for VSS input to be 0 mph when vehicle transmission is in Park.