DTC B124: Vehicle Speed Sensor (VSS) Circuit Problem: Description

The vehicle speed sensor uses a Permanent Magnet Generator (PM) to generate an electrical signal representative of vehicle speed. This signal is brought to the BCM by circuit No. 400 (VSS high) and circuit No. 401 (VSS low), where the BCM buffers and amplifies the signal for its prospective uses. Output of the generator can be seen by using a digital voltmeter on the AC scale while rotating the generator drive (rotate front wheels).

Code B124 will set if the following conditions maintain for at least 30 seconds. Ignition switch turned to ON position, no Code EO28, no Code B334 or EO47, transaxle in 4th gear (EI82 "LOW"), no VSS input to the BCM from the ECM, and engine speed greater than 1300 RPM.