Powertrain, generic (extended)

P2D4B Hybrid/EV Battery Pack G Over Temperature

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2D4B reports overheating in section G, the seventh separately supervised part of the traction battery. Such a letter only makes sense for big packs with many groups. The Audi Q5 PHEV is a documented example of such a split: its hybrid battery unit 008C reports eight battery groups through the deterioration codes P0A7F00 to P2CCD00, group 7 being P2CCC00, and Audi bulletins 2076982/1 and 2079556/1 of 2025 deal with replacing single modules. Those bulletins cover ageing only; no manufacturer documents P2D4B. For battery components such as cells and temperature sensors, CARB requires codes that isolate the smallest unit replaceable in service. Before a module is changed, the cooling circuit for section G should be checked, since overheating alone is not proof of a worn module.

Likely causes

Insufficient cooling of section G (coolant distribution, trapped air, pump)
Worn module in section G (compare with P2CCC)
Temperature sensor of section G reading too high

Symptoms

  • Engine or hybrid warning lamp
  • Displayed electric range shorter than usual
  • Reduced charging power

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€100–4,000
Time1–10 h

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

Parts involved

hv battery pack gbattery thermal managementbattery energy control module

Related codes

P2D4AP2D4CP2CCCP0A7EP0A7F

References: law.cornell.edu, static.nhtsa.gov, static.nhtsa.gov.