Powertrain, generic · Hybrid propulsion

P0DDA Hybrid/EV Battery Cell Balancing Circuit L Stuck Off

Check engine lightOn

EmissionsRelevant

Drive cycleRequired

Limp modeNo

P0DDA says circuit L does not discharge when it is told to. In Ford's 2019 hybrid OBD summary the start-up test has been simplified: it still runs for 100 ms before the contactors close, but the requirement of two consecutive power cycles is gone, and the 75 mV deviation of a cell from the average must instead persist for 0.1 s. Ford's 2014 code list flags the code for the MIL. Renesas patent US9735567B2 explains why a switch that never closes can be seen electrically: a pull-up lifts the balancing pin to cell potential, so a switch that is told to close while the pin still shows the full cell voltage means the path is open. Group L then lags behind in every balancing run and limits the charge. Opposite case: P0DD9.

Likely causes

Balancing switch of group L stays open when commanded on

Bleed resistor of circuit L open

Missing gate drive for the balancing switch of L

Symptoms

Check engine light with no change in drivability
Group L reaches full charge before the rest
Gradual loss of usable capacity

Repair estimate

DifficultyShop_onlyWorkshop job

Parts and labour€300–4,500

Time1.5–8 h

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

Parts involved

hv battery cell balancing circuit lbms

References: law.cornell.edu, fordservicecontent.com, patents.google.com, performanceparts.ford.com.