Diagnostic article Generic OBD-II
P0D5B: low-voltage charger power fails an input-to-output plausibility check
GM P0D5B compares calculated low-voltage output power with an AC-input-based boundary, after excluding specified sensor faults.
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Documented application
GM 2015 15OBDG01 Hybrid Diagnostics, only the cited EACCM monitor and calibration. Per-code vehicle and engine applicability has not been established; these historical thresholds are not universal service specifications.
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.
P0D5B asks whether the charger's reported low-voltage output power is plausible relative to its AC input information. It combines output voltage and current. This makes it a consistency check involving several measurements, rather than a direct test of auxiliary-battery capacity.
Valid inputs are prerequisites
GM excludes the listed low-voltage current-sensor, voltage-sensor and reference-voltage faults. AC input-power status must also not be failed. Those prerequisites matter because a bad input can invalidate a power calculation before any conclusion about conversion performance is justified.
The failure must occupy 1.6 seconds within a two-second window. The printed calibration boundary uses AC input power multiplied by 1.9995, plus a 125 W offset. Although the explanatory text calls the multiplier efficiency, this article does not interpret that number as a physical conversion-efficiency percentage; that wording requires clarification.
Trace the calculation before blaming a component
Record the AC input-power value and the low-voltage output voltage and current together. The diagnostic question is which inputs account for the implausible calculated result, not merely whether a charger-related code is present.
The sheet does not establish a failed converter or a prescribed battery replacement. It also provides no external load-test setup. Use the matching vehicle diagnostic procedure to assess measurement accuracy and actual output behavior. Physical work on a charger requires professional high-voltage precautions even when the calculation being investigated concerns its nominal 14 V output.
Source and applicability
GM 2015 15OBDG01 Hybrid Diagnostics, only the cited EACCM monitor and calibration. Per-code vehicle and engine applicability has not been established; these historical thresholds are not universal service specifications.
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
Battery Charger 14 Volt Output Power Performance
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