Powertrain, generic (extended)

P2D3B Hybrid/EV Discharge System Fault

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

After the contactors open, the capacitors of inverter and DC link still hold high voltage, so a discharge system, either a resistor or an active circuit in the power electronics, drains them within seconds. P2D3B is the general fault code for this system; the narrower ones are P0C75 and P0C76 for discharge time and P0EED for the discharge circuit. No manufacturer documents P2D3B publicly. GM's 2019 hybrid table shows how the drain is checked under P0C76: if the inverter still reads above 200 V 3.5 s after the main contactors opened, a Type A fault is set after two runs. Volkswagen patent US9586481B2 requests active discharge after a severe crash and treats it as complete below about 60 V. The car may refuse to restart, and nobody should work on the system without measuring that it is voltage-free.

Likely causes

Faulty active discharge switch or driver in the inverter
Open or degraded passive discharge resistor
Wrong high-voltage reading in the inverter or battery module
Contactor that does not open, so the bus stays fed from the battery

Symptoms

  • Hybrid/EV system warning lamp on
  • Vehicle does not become ready on the next start

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€150–3,000
Time1–6 h

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

Parts involved

hv battery discharge circuitdischarge resistordc link capacitor

Related codes

P0C76P0C75P0EEDP0D5EP2D39

References: gsi.ext.gm.com, patents.google.com, law.cornell.edu.