Diagnostic article Generic OBD-II
P05D2: driver-mode switch voltage exceeds the documented high limit
The selected 25OBDG04B BCM monitor assigns P05D2 when driver-mode analog switch bank 1 input exceeds 4.7220 V.
Read before applying this article
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.
The selected 25OBDG04B BCM monitor assigns P05D2 when driver-mode analog switch bank 1 input exceeds 4.7220 V. It is a circuit-range result rather than a statement that a particular driving mode is mechanically unavailable.
Configuration and duration matter
General switch-bank diagnostics, circuit diagnostics and the high-range test must all be calibration-enabled. The failure occupies four seconds within a five-second window and uses Type B, two-trip reporting.
The page also includes a smart-switch-bank ignition-delay condition with inconsistent TRUE/FALSE wording. Its exact applicability needs service-information review; establish the installed switch architecture rather than assume every bank uses an identical wake-up sequence.
Interpret the high value without guessing a part
The voltage boundary belongs to this cited calibration. Another implementation of P05D2 can have a different threshold, so use the vehicle's actual service definition before judging a borderline reading.
A useful verification captures the bank input after the applicable enabling conditions and confirms stable recognized switch states. A momentary normal voltage or one successful mode change is not equivalent to an entire eligible observation window. The source does not identify a shorted wire, failed switch or controller input by itself. It provides detection logic, not a pinout or instruction to replace the switch bank, and does not authorize bypassing the mode-selection circuit.
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 79.
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 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