P0B45: sense circuit C should be read alongside adjacent channels

P0B45 identifies battery voltage-sense circuit C in the cited GM diagnostic summary. The monitor family detects an open sensing condition using relationships between measured cell voltages and, for some cases, busbar-related values.

Do not diagnose from one channel alone

The general sensing-line branch compares the affected reading with an adjacent reading. The shared-power branch also uses adjacent-cell behavior, with a different difference threshold. These distinct patterns show why a single unusually high or low value is not enough to choose a repair.

Those cases apply to the family; the document does not claim that circuit C has a special failure cause unavailable to the other channels. The useful code-specific information is the identified C channel, which must be matched to the correct vehicle wiring and pack layout.

Establish whether the monitor could run

The table requires diagnostic and communication enables and excludes specified sensing-module communication failures. Its continuation adds internal-performance and balancing restrictions. A non-returning P0B45 during those faults cannot automatically be counted as a successful sensing-circuit test.

One busbar-positive comparison is incomplete in the source. This draft retains that limitation instead of inventing the missing threshold.

Preserve the C-channel value, neighboring values, module status and event timing. A trained battery technician can then distinguish an open measurement path from genuine cell behavior using the approved service process. The code alone does not justify live probing or cell replacement.

Application limits

Document-level 2015 GM diagnostic table; per-code vehicle/engine/calibration applicability not established.

Source

15OBDG01 Hybrid Diagnostics, physical PDF pages 635, 636.