P0DAD code meaning
Hybrid/EV Battery Cell Balancing Circuit A Stuck On
Powertrain system Generic code P0Dxx codes Check engine light
What P0DAD means
P0DAD means balancing circuit A keeps draining its cells although the controller has not asked for it: the bleed switch is stuck closed and the resistor keeps pulling those cells down. Ford uses the code in the BECM of its hybrids; the 2019 OBD summary gives each of 14 circuits six cells and, at key-on with the contactors still open, rates a circuit faulty when one of its cells departs from the mean for 0.1 s by over 75 mV. Toshiba's patent US20130026994A1 detects such a shorted balancing switch with a comparator. Left alone, the affected cells sink below the rest, particularly while the car is parked, and the usable pack window shrinks. Which cells form group A is up to the maker.
P0DAD at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor2 to 8 hours
- Clears after repairAfter a drive cycle
Symptoms of P0DAD
- Hybrid or EV battery warning with the MIL
- Cells of one group noticeably lower after the car has been parked
- Range or electric assistance decreasing over days
Common causes of P0DAD
- Most likelyBalancing transistor of circuit A shorted (fails closed)
- PossibleMonitoring chip or its drive output keeps the switch enabled
- Less likelyController software leaving a balancing request active
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Hv battery cell balancing circuit aBms
What each part of P0DAD means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| AD | The exact fault in that area. |
What to do next
- Note P0DAD and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0DAD
What does P0DAD mean?
P0DAD means "Hybrid/EV Battery Cell Balancing Circuit A Stuck On". P0DAD means balancing circuit A keeps draining its cells although the controller has not asked for it: the bleed switch is stuck closed and the resistor keeps pulling those cells down. It is a generic code, so it means the same on every make.
Is it safe to drive with P0DAD?
Drive gently and only to a workshop. With P0DAD the car can go into limp mode (reduced power) to protect itself.
Will P0DAD fail an emissions test?
Yes, it can. P0DAD is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0DAD to fix?
Difficulty: workshop only. A typical repair takes 2 to 8 hours of work. This is a job for a workshop.
Will P0DAD clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.