Diagnosis Description
WARNING: This page is about a different car, the 2008 Infiniti M45 and 2008 Infiniti M35. However, it is still accessible from the selected car via links, so may be relevant.
B2557 vehicle speed signal compares the vehicle speed input from the unified meter and A/C amp. and ABS via CAN communication and the vehicle signal (8 pulses) from the unified meter and A/C amp. If there is the difference between each vehicle speed input, it judges that it is the malfunction and displays the DTC (Diagnostic Trouble Code).