P0DBC: Hybrid/EV Battery Cell Balancing Circuit E

What does P0DBC mean?

P0DBC is set for an electrical fault in the fifth balancing channel, E: the controller cannot trust the path through which group E would be bled, because a lead, switch or resistor reads open, shorted or out of range. The floating-capacitor method in LG Chem's US20110285539A1 is one way to test that path without loading the cells: charge, discharge through the balancing circuit, then compare the residual voltage with a limit. CARB 13 CCR 1968.2 requires the balancing parts of a hybrid to be monitored. In bulletin 93 17 04 from Audi, covering the A3 e-tron of model year 2016, P0DBC00 appears with the circuit codes of A to H; late CAN start-up was the cause, removed by software for the battery controller at address 008C.

The code tells you which monitor failed, not which part is broken. Test before replacing parts.

Symptoms

• MIL and battery warning
• Electric drive possibly restricted

Common causes

• High Open or shorted balancing lead in group E
• Medium Monitoring chip responsible for group E faulty
• Low Module connector of group E loose or corroded

Likelihood is a general estimate across vehicles; your make and model may differ.