P0B70: interpret block 11 high as a measurement finding

P0B70 is the high-range member of the block 11 voltage-monitor family in this GM document. Generic readers may display voltage sense K high. Both descriptions point to a measurement channel, while the document supplies the controller's particular detection rule.

Range and plausibility are different questions

A block 11 reading greater than 23 V is the published high criterion. The failure must occur in fifteen of twenty samples, taken at 100 ms intervals. These values are specific to the historical monitor and should not be adopted as specifications for a different battery design.

The adjacent performance code uses block-to-pack calculations and a longer sample counter. Consequently, a high-range report and a rationality report should be recorded separately, even when they appear during the same visit. They do not demonstrate identical tests or identify identical causes.

Preserve the surrounding evidence

Useful records include the block 11 trace, associated pack measurements, fault status and low-voltage supply condition. P0A1F inhibits this monitor; RUN mode and a 9–18 V supply are also required. A test conducted without those prerequisites cannot establish that the high branch now passes.

The source does not name a failed cell, prescribe a replacement pack or provide connector measurements. Physical verification of the sensing path belongs within the correct hybrid service procedure. Avoid inferring actual battery overvoltage solely from one controller-reported channel.

Source and applicability

GM 2010 10OBDG10 Hybrid Diagnostics, cited BPCM or hybrid-controller monitor only. Historical calibration values are not universal specifications; no per-code model, engine or hardware fitment has been established. GM PDF, physical page 228.