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P2D2B

Hybrid/EV Battery Pack Coolant Temperature Sensor A/B Correlation

The signals of the HV battery pack coolant temperature sensors A and B do not correlate within the calibrated tolerance. One sensor drifts or installation offset between channels.

  • Check engine light: Yes
  • Emissions related: No
  • Repair difficulty: easy

Symptoms

  • EV/hybrid system warning light on
  • Reduced power output or limp mode
  • Charging may fail or be slowed
  • Reduced electric range

Common causes

Ordered by how often each turns out to be the cause.

  • One sensor characteristic driftedCommon
  • Harness incorrectly swapped between channelsPossible
  • Pack cell imbalance approaching service thresholdLess likely

Parts involved

  • Hybrid Battery Coolant Temp Sensor A
  • Hybrid Battery Coolant Temp Sensor B
  • Bms

P2D2B is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.