P0DC4Hybrid/EV Battery Cell Balancing Circuit G
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- 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.
- What you may notice
- Hybrid battery warning with check engine light
- External charging refused now and then
- Scan tool lists several circuit codes plus a control module fault
- Likely causes
- LikelyCommon software or communication cause when circuit codes A to H appear together (Audi A3 e-tron)
- PossibleBleed FET of channel G failing the on-state check
- RareCorroded or loose connector on the cell harness of group G
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €100 – €4,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.