Powertrain, generic · Hybrid propulsion

P0DC4 Hybrid/EV Battery Cell Balancing Circuit G

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0DC4 points to the hardware path of balancing circuit G: lead, switch, resistor or the chip that drives them. On the 2016 Audi A3 e-tron it appears as P0DC400 in bulletin 93 17 04, never alone but in a row with the circuit codes of groups A to H. When so many channels fail at once, a shared cause is far more likely than eight broken circuits; Audi blamed late CAN start-up and fixed it with software for J840 and JX1. A genuine defect looks different: Texas Instruments describes for its BQ79616-Q1 monitor a test that turns the bleed FET on and expects the voltage across it to fall below half the cell voltage; a channel that fails this is singled out. Supervision of these parts is mandated in CARB's OBD regulation, 13 CCR 1968.2. Siblings: P0DC5 to P0DC7.

Likely causes

Common software or communication cause when circuit codes A to H appear together (Audi A3 e-tron)
Bleed FET of channel G failing the on-state check
Corroded or loose connector on the cell harness of group G

Symptoms

  • Hybrid battery warning with check engine light
  • External charging refused now and then
  • Scan tool lists several circuit codes plus a control module fault

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€100–4,000
Time0.5–8 h

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

Parts involved

hv battery cell balancing circuit gbms

Related codes

P0DABP0DC5P0DC6P0DC7P0DC0P0DC8

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