P0B13: fine and coarse battery-current measurements disagree

P0B13 in the cited GM hybrid summary checks agreement between fine and coarse battery-current measurements. It evaluates the absolute difference between the two readings, rather than simply testing whether either reading is above a single high-current limit.

Compare the channels inside their shared range

The documented difference threshold is ten amperes. The enable logic requires one of the current readings to be within the stated fine-range window. This matters because comparing channels outside the intended overlapping range can misrepresent their expected agreement.

The check also excludes several current-sensor and communication faults. A channel already known to be electrically invalid cannot provide a trustworthy comparison. Record both signed readings from the same operating interval rather than compare unrelated snapshots.

A disagreement does not identify the wrong sensor

The absolute difference shows that the channels do not agree sufficiently. It does not, by itself, establish which sensor is biased or whether a supporting circuit caused the difference. The applicable service procedure must resolve that question.

The printed inhibit list includes P0B13 itself. Its precise relationship to the monitor's active/latched status is not explained in this summary, so this draft does not invent a reset or re-enable instruction.

Preserve the paired readings, current-range condition and companion codes before clearing data. High-voltage battery-current diagnosis requires qualified equipment and isolation procedures; the correlation result is not a reason to probe live battery conductors.

Application limits

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

Source

15OBDG01 Hybrid Diagnostics, physical PDF pages 585.