P0DD6: Hybrid/EV Battery Cell Balancing Circuit K Stuck Off

P0DD6: group K's bleed path stays dead when balancing is called for. Ford includes it in its 2017 hybrid OBD summary; the BECM decides at power-up with open contactors, within 100 ms and over two power cycles, using the 75 mV deviation of one of the six cells from the average. LG's patent US20110285539A1 offers a direct check of the path: a sampling capacitor first takes on the cell's voltage and is then emptied through the balancing circuit; whatever voltage is left over must be close to zero, otherwise the circuit is faulty. Because nothing is drained, the car drives normally, but group K keeps reaching full charge first and the pack loses usable capacity. The stuck-on counterpart is P0DD5.

High severity. Can I keep driving?If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.

Symptoms

Check engine light while the car drives normally
Group K highest at the end of charging
Electric range decreasing over many charges

Most likely causes

Open bleed resistor in circuit K
Balancing switch of group K failing to turn on
Cracked solder joint in the balancing path of K

What to check, in order

Start with the simplest. You can tick off each step.

Read the codes with a hybrid-compatible scanner and write down the freeze frame data
Use the scanner to command the movement and compare the actual position with the requested one.
Make sure the battery cooling air intake is clean
Check the 12 V auxiliary battery, which can also trigger warnings
Leave any high-voltage measurements to a specialized repair shop

Good to know

It affects emissions.

What each character of P0DD6 means

P: Powertrain: engine and transmission
0: Generic code: same on every make
D: Subsystem depends on the code range
D6: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0DD6?

If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.

What causes code P0DD6?

The most common causes are: open bleed resistor in circuit K; balancing switch of group K failing to turn on; cracked solder joint in the balancing path of K.

Related codes

Sources

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.