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

The vehicle speed sensor uses a permanent magnet (PM) generator to produce an electrical signal representative of vehicle speed. This signal is sent to the ECM by CKTs 400 (VSS HI) and 401 (VSS LO) where the ECM 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 are present for 30 seconds:

• Ignition Switch is turned to ON position.
• Transaxle in 4th gear (EI82 "HI").
• Engine RPM greater than 1300.
• No vehicle speed input to the BCM from the ECM.

During the time the failure is present the continuous compressor at idle will be disabled.