Powertrain, generic · Hybrid propulsion

P0DC8 Hybrid/EV Battery Cell Balancing Circuit H

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0DC8 covers an electrical fault of balancing circuit H. Audi's bulletin 93 17 04 for the 2016 A3 e-tron lists P0DC800 as the last of its circuit codes; no letter beyond H appears there, which suggests eight circuits in that pack. Since the fix was software that let CAN communication begin on time, the entry can also stem from the controller not hearing its cell electronics early enough. GM's eAssist table 13OBDG05C shows the same idea under its own codes: losing LIN contact with a balance processor (P1B34, P1B35) counts as a fault after 7 of 10 checks every 200 ms and is rated Type B. California makes this supervision mandatory for hybrid OBD. Stuck and plausibility faults of H use P0DC9 to P0DCB.

Likely causes

Cell electronics not answering in time after wake-up (Audi software fix)
Damaged internal bus or supply wiring to the monitoring board of group H
Open bleed path or lead in circuit H

Symptoms

  • Charging not possible at times
  • Hybrid battery warning and check engine light
  • Fault returns after clearing until software is updated

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 hbms

Related codes

P0DABP0DC9P0DCAP0DCBP0DC4P0DCC

References: law.cornell.edu, static.nhtsa.gov, gsi.ext.gm.com.