Diagnostic article Generic OBD-II
P0B46: Blocks three and four are both part of the block-three plausibility test
Understand the GM P0B46 paired comparison with pack voltage and its contactor-state prerequisites.
Read before applying this article
Documented application
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.
The code alone does not identify a failed part or establish that a vehicle is safe to drive. Confirm the vehicle, reporting module and applicable service procedure.
P0B46 is the block-three rationality monitor in the cited GM battery controller. The title names block three, but the failure calculation also evaluates block four. Each reading is scaled by twenty before comparison with the dedicated pack-voltage sensor.
Two independent differences must qualify
Both absolute scaled differences must exceed 70V. One discrepant block reading alone does not satisfy the full AND condition. The controller requires block three's input to be valid and excludes its low/high circuit faults and the specified pack-voltage/controller faults.
Evaluation occurs in run mode after more than 200ms since contactor closure. The failing-sample decision is 160 out of 170 at 100ms intervals, making sustained comparison data more informative than a single snapshot.
Preserve the complete calculation
Capture block three, block four and the independent pack voltage with their status and timing. Do not interpret the scaled 70V mismatch as a direct allowable difference between neighboring blocks. That would be a different calculation from the one GM prints.
The table does not reveal the sensing-harness topology or prove that both battery blocks are defective. The applicable service diagram and circuit tests must establish the cause. Physical pack diagnosis belongs with trained high-voltage personnel following prescribed isolation and verification; this monitor explanation supplies no live-probing or module-replacement procedure.
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.
Article source documents
Source checks describe how the text was prepared; they do not certify a diagnosis or confirm compatibility with every vehicle using this code.
Original code reference
Dictionary definition
Hybrid/EV Battery Voltage Sense C Circuit Range/Performance
This definition retains its original catalog scope. The article above is limited to its explicitly documented application.
Reference scope
Generic OBD-II definition.
A manufacturer label does not establish the model, year, engine or module to which a diagnosis applies. Read the safety and diagnostic limits.
Definition source
- DTC Database: pinned community code definitions
Source checked · MIT