Powertrain, generic (extended)

P2E70 Hybrid/EV Battery Pack B Cell Thickness

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2E70 is the swelling code for a second high-voltage pack, B, in vehicles that carry two; which pack is A and which B is set by the maker. The controller judges that cells in pack B have grown too thick. No manufacturer documents P2E70 publicly. Research explains why thickness is watched at all. A University of Michigan patent reads the force on the module end plates and uses it to estimate capacity loss, and Southwest Research Institute derives aging from the strain at equal charge level, new versus aged. In real failures far more happens: in tests by the UK HSE a heated 5 Ah pouch cell released about 4 litres of gas on average, and the force of that swelling matters most where cells sit tightly packed. Pack A swelling is P2E6C.

Likely causes

Cells in pack B aged and permanently thicker
Gas generation after overcharge, deep discharge or heat
Poor cooling of pack B accelerating cell degradation

Symptoms

  • Hybrid or EV warning with power reduction
  • Reduced range or charging blocked
  • Vehicle may refuse READY

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€600–9,000
Time2–10 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

hybrid battery pack bhybrid battery pack b thickness sensorbms

Related codes

P2E71P2E72P2E73P2E6CP0EDDP2D46

References: law.cornell.edu, image-ppubs.uspto.gov, image-ppubs.uspto.gov, icheme.org.