P0B97: the block 19 low code uses the final neighboring block

P0B97 is block 19 voltage measurement out of range low in GM's table. A generic description uses voltage-sense circuit S low. The diagnostic significance comes from the complete row, which also uses block 20 rather than judging the named channel alone.

Preserve the adjacent pair

Both block 19 and block 20 must read below 2 V. A useful diagnostic capture includes those two values at the same operating moment. A later isolated low value cannot show whether the controller's paired condition was satisfied during the original event.

GM confirms fifteen failures among twenty samples, with a 100 ms sample interval. The published two-trip Type B classification is separate from that repeated-sample rule and should not be used to promise a particular warning-lamp clearing schedule.

Check eligibility and measurement integrity

The BPCM must be in RUN with the 12 V supply between 9 and 18 V. P0A1F must not be active. These prerequisites affect whether a retest can evaluate the channel after codes are erased.

The source establishes a reported low pattern, not a conclusive diagnosis of a damaged block or depleted battery. The applicable sensing-circuit procedure is needed to distinguish actual voltage from inaccurate measurement. A qualified hybrid technician should perform physical checks under the correct high-voltage precautions; the monitor table itself contains no safe battery-opening instructions.

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 232.