Powertrain, generic (extended)

P2E73 Hybrid/EV Battery Pack B Cell Thickness Sensor Circuit Performance

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P2E73 indicates that the thickness sensor of pack B delivers values within range that the controller cannot reconcile with what it otherwise knows about the pack. Free expansion of a healthy cell is small, about 1 % of its thickness on the Ford Fusion HEV cell measured by GE, so a sensor must resolve fractions of a millimetre; GE's thin eddy-current coils between cells covered 0 to 2 mm. Plausibility can also come from other signals: LG patents detecting swelling from the temperature sensors already in a module, and the Michigan force method links end-plate load to capacity fade, giving references to compare against. No manufacturer documents P2E73 publicly. CARB asks for rationality checks where feasible; pack A's version is P2E6F.

Likely causes

Sensor mounting or gap changed, for example after module work
Sensor drift or degraded sensing element
Plausibility limits in the battery controller software too tight

Symptoms

  • Warning light, often with no other complaint
  • Battery controller may limit power or charging rate

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€150–2,500
Time1.5–8 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

P2E70P2E71P2E72P2E6F

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