P0B41: Block-two rationality also depends on the block-three comparison

P0B41 is labeled block-two voltage rationality in this GM table, but its failure criterion includes both block two and block three. Each block reading is multiplied by twenty and compared independently with dedicated pack voltage.

Both scaled differences must exceed the limit

The absolute block-two comparison must exceed 70V and the block-three comparison must also exceed 70V. The conjunction matters: a discrepancy involving only block two is not the complete printed P0B41 condition.

The monitor requires block two's input to be valid, battery-controller run mode and more than 200ms after contactor closure. Block-two circuit limits and the listed pack-voltage/controller faults must be inactive. Failure uses 160 qualifying samples within 170 at 100ms intervals.

Preserve the neighboring channel

Record block two, block three and the independent pack-sensor value together. Capturing only the channel named in the title would omit half of the monitored relationship. The twenty-times scaling also means the 70V difference is not a direct allowable voltage error across one block.

The document does not prove a shared wire fault or explain the physical sensing topology. Those details require the correct battery diagram. A trained high-voltage technician must perform any physical diagnosis under the prescribed isolation procedure; neither a rationality code nor low displayed block values establish that pack access is safe.

Source and applicability

GM 2010 10OBDG10 Hybrid Diagnostics, only the cited controller and monitor. These are historical calibration examples; individual vehicle, engine and hardware applicability is not established. GM PDF, page 223.