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DTC codes / P0Exx · Hybrid propulsion / P0E45

P0E45Hybrid/EV Battery Pack Voltage Sense E Circuit Range/Performance

P0E45 means the hybrid or electric vehicle battery pack voltage sensing circuit E is reporting a voltage reading outside the range the computer expects, or the signal is not changing as it should. The computer compares this sense circuit against other voltage sense circuits and flags the code when the reading is implausible or inconsistent.

SystemPowertrain
Code typeGeneric (all makes)
SeverityMedium
Fix difficultyProfessional
AreaHybrid propulsion

Symptoms you may notice

  • Often no symptoms besides the warning light, especially if the fault is intermittent
  • Reduced electric-only driving range or the vehicle refusing to enter EV mode
  • A sudden drop in state of charge or erratic battery gauge behavior
  • Reduced power output or limp mode under acceleration
  • Charging faults or the vehicle failing to start a charge session
  • Other hybrid system warnings displayed alongside the check engine light

Common causes, most likely first

  1. A faulty voltage sense wire or connector at the battery pack, often due to corrosion or vibration damage
  2. A failed battery pack voltage sense module or sensing harness internal fault
  3. A weak or failing hybrid/EV battery pack cell or module causing an abnormal voltage split
  4. High-voltage interlock or service disconnect plug not fully seated or damaged
  5. A software or calibration issue in the battery energy control module
  6. Water intrusion or contamination in the battery pack connector area
  7. A failing battery energy control module itself, though this is less common

How to diagnose and fix it

  1. Scan all modules and record freeze-frame data for P0E45 and any companion codes before clearing anything
  2. Inspect the battery pack voltage sense connectors and harness for corrosion, looseness, or chafing
  3. Measure the sense circuit voltage at the module connector and compare it with a known-good sense circuit
  4. Check the high-voltage service disconnect and interlock circuits for proper seating and continuity
  5. Perform a battery pack voltage balance check with a scan tool to see if one module is out of line
  6. Verify battery energy control module software is up to date and apply any available calibration updates
  7. If the sense circuit and pack voltages check out, substitute a known-good sense module or control module to confirm the fault

What the voltage sense E circuit really checks

  • This code often sets from a poor connection at the battery pack sense connector rather than a failed battery, so a careful wiggle test and terminal inspection can save a pack replacement.
  • A single weak cell or module can skew the voltage split enough to trigger a range/performance code on one sense circuit without setting a low-voltage code for the whole pack.
  • Technicians sometimes replace the battery energy control module when the real problem is a chafed sense wire routed near a sharp bracket or heat source.
  • The code can be intermittent and only appear during high-load events or temperature extremes, so freeze-frame data is more useful than a static voltage reading.
  • After any repair, the battery energy control module may need a relearn or adaptation drive before the code will clear and stay cleared.

Can I keep driving with P0E45?

You can usually drive the vehicle short distances to a repair shop, but avoid heavy acceleration, long trips, and charging if the battery gauge behaves erratically. If the vehicle enters limp mode or shows a high-voltage warning, stop driving and have it towed.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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