What Does P0B49 Mean?
DTC P0B49 indicates the hybrid battery voltage sense "C" circuit is producing intermittent or erratic readings at the individual module level. The BMS detects voltage signals from the "C" module that fluctuate unpredictably, suggesting a connection issue rather than an actual cell voltage problem. This intermittent pattern is most commonly caused by loose connections or degraded wiring at the module level.
Common Causes
35%
Loose or intermittent connector at the "C" module voltage tap
25%
Partially broken or chafed sense wiring near the module
20%
Corroded cell tap terminal on the "C" module
12%
Failing cell monitoring IC with intermittent internal fault
8%
Vibration-induced contact issues in the module assembly
Diagnostic Steps
1
Review freeze frame data to identify driving conditions (vibration, temperature) when erratic readings occur.
2
Perform a wiggle test on the "C" module connections and sense wiring while monitoring live voltage data.
3
Inspect the "C" module cell tap and connector terminals for corrosion, heat discoloration, or loose fit.
4
Check the sense wiring routing near the module for chafing against mounting hardware or adjacent components.
5
If no physical fault is found, monitor the module voltage during varied driving conditions to characterize the intermittent pattern.
Estimated Repair Cost
$200 - $1,800
Parts + labor, varies by vehicle and location
DTC P0B49 indicates the hybrid battery voltage sense "C" circuit is producing intermittent or erratic readings at the individual module level. The BMS detects voltage signals from the "C" module that fluctuate unpredictably, suggesting a connection issue rather than an actual cell voltage problem. T...
The most common cause of P0B49 (Hybrid Battery Voltage Sense "C" Circuit Intermittent/Erratic) is: Loose or intermittent connector at the "C" module voltage tap
Typical repair costs for P0B49 range from $200 to $1,800, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Intermittent module voltage readings prevent reliable BMS monitoring of that cell group. While less immediately critical than a sustained fault, it can mask developing cell problems and lead to incorrect charge balancing decisions.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0B49 to identify the root cause.
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Quick Info
Category
Powertrain
System
Hybrid/EV Battery System
Difficulty
Type
Generic (SAE)
Recommended Tools
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