Diagnostic article Generic OBD-II
P06B1: speed-sensor supply switch current or temperature fault
P06B1 is cataloged as sensor power supply A circuit low, but the cited transmission implementation monitors the VSS1 supply switch for overcurrent or overtemperature.
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Documented application
2025 GM 25OBDG07A Part2 diagnostic monitor documentation; the application-matrix filename mismatch is unresolved, so no model or engine applicability is inferred.
The code alone does not identify a failed part or establish that a vehicle is safe to drive. Confirm the vehicle, reporting module and applicable service procedure.
P06B1 is cataloged as sensor power supply A circuit low, but the cited transmission implementation monitors the VSS1 supply switch for overcurrent or overtemperature. The label alone therefore does not describe the actual test quantity.
Two switch reports share the code
The row lists supply current above 220 milliamperes or a switch-overtemperature report as failure evidence. The condition must qualify for at least 60 milliseconds. No numerical switch-temperature threshold is supplied, so one should not be invented from the current limit or nearby tables.
Battery voltage must lie between 8.75 and 18 volts, the engine must not be cranking, and key status must not be Stop. P0882 and P0883 disable this continuously scheduled diagnostic.
How this changes the next check
A low supply reading might be relevant context, but it does not distinguish an overcurrent report from a thermal report. Preserve the switch status and available current information, not just the generic code description. Conversely, absence of an electrical speed-signal fault does not prove the supply switch passed.
Verification should show the enabled VSS1 switch monitor completing without either failure report. The table supports investigating the protected supply circuit, but does not identify a shorted sensor or require replacement of the transmission controller from this code alone.
Documentation and applicability
These details describe the monitor in GM’s 2025 25OBDG07A Part2 file. Its application-matrix filename does not match the download index, so model and engine applicability remain unresolved. Use the vehicle’s correct service information before applying these calibration details.
Article source documents
Source checks describe how the text was prepared; they do not certify a diagnosis or confirm compatibility with every vehicle using this code.
Original code reference
Dictionary definition
Sensor Power Supply A Circuit Low
This definition retains its original catalog scope. The article above is limited to its explicitly documented application.
Reference scope
Generic OBD-II definition.
A manufacturer label does not establish the model, year, engine or module to which a diagnosis applies. Read the safety and diagnostic limits.
Definition source
- DTC Database: pinned community code definitions
Source checked · MIT