Diagnostic article Generic OBD-II
P05D1: driver-mode switch bank 1 input below its low threshold
P05D1 checks the analog driver-mode switch bank 1 for an out-of-range low input.
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Documented application
2025 GM 25OBDG04B diagnostic parameter tables; the cited monitor only. Vehicle, engine and calibration applicability must be confirmed separately.
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.
P05D1 checks the analog driver-mode switch bank 1 for an out-of-range low input. In the cited 25OBDG04B BCM row, the threshold is below 0.5280 V.
Use a calibration-specific voltage
This value describes the selected source's switch-bank implementation. It is not a universal threshold for every vehicle that uses P05D1; the switch's resistor network and controller calibration must match before applying it.
The table requires the bank's general diagnostic, circuit diagnostic and low-range diagnostic to be enabled by calibration. The low input must occupy four seconds within a five-second window, with Type B reporting over two trips.
Separate a persistent low input from an ambiguous state
An input below the low boundary differs from a voltage that remains within the overall span but falls between recognized switch states. Keeping the actual voltage and duration changes which diagnostic condition is being assessed.
Verification should establish that the relevant bank is configured and its input remains in the proper valid ranges during an eligible observation period. A single successful mode selection does not prove that an intermittent low reading has been resolved. The source does not identify the failed connection or switch element and supplies no component location, replacement instruction or indication that a driver-selected mode should be forced through a bypass. Match the circuit to the exact vehicle service procedure.
Source and applicability
2025 GM 25OBDG04B diagnostic parameter tables; the cited monitor only. Vehicle, engine and calibration applicability must be confirmed separately. These tables describe detection logic, not a complete repair procedure or a component replacement verdict. gm-2025-04b, PDF page 78.
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
Driver Mode Select Switch 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