Diagnostic article Generic OBD-II
P06A5: Reference D high can be a 10.5-volt speed-sensor supply check
P06A5 in this TCM monitors VSS1 above 10.5 volts, so a generic five-volt reference assumption would use the wrong circuit.
Read before applying this article
Documented application
2025 GM 25OBDG07A Part 2, specific documented monitor only. Vehicle, engine and calibration applicability require confirmation; application-matrix filename join is unresolved.
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.
P06A5 is generically named sensor reference voltage D high. In the cited GM transmission controller, that code monitors speed-sensor supply VSS1. Its operating range is different from the five-volt reference rails elsewhere in the same document.
The actual rail matters more than the letter
The high boundary is VSS1 above 10.5 volts, with 500 millivolts of hysteresis and a confirmation time of at least 75 milliseconds. Applying a five-volt-reference expectation to this rail would misinterpret the documented system.
The main battery must be above 8.75 and below 18 volts. Cranking and the STOP key state are excluded, and P0882 or P0883 disables the monitor. The check runs continuously when these conditions allow it.
Keep supply diagnosis separate from speed plausibility
A speed value that looks implausible may motivate investigation, but P06A5 here concerns the electrical supply feeding the speed-sensor system. Preserve VSS1 voltage and eligibility information rather than relying solely on wheel or shaft-speed values.
The source does not provide a distribution map or identify which connected element raised the supply. Use the applicable transmission wiring and circuit procedure to localize the issue. A normal VREF reading on another rail cannot confirm this fault is resolved. Verification must concern the VSS1 supply under the documented qualified conditions, with the correct calibration limits.
Source and applicability
This explanation covers the cited GM monitor, not every vehicle carrying this code. The application-matrix filename does not resolve cleanly to this file, so no model or engine fitment is assigned. GM diagnostic table, PDF page 908.
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 Reference Voltage D Circuit High
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