P0B72 code meaning
Hybrid/EV Battery Voltage Sense L Circuit
Powertrain system Generic code P0Bxx codes Check engine light
What P0B72 means
P0B72 reports an open circuit on voltage sense L, the twelfth channel. One detail sets it apart from its neighbours: GM's 2011 hybrid tables list every open sense line code from P0B3B upward except P0B72 (and P0B90), so the early system did not use it, while L's range, low and high codes were present. Later GM tables include it. The BAS Plus mild hybrid sets it when lines N and N-1 fall below 1.4 V with a change above 0.5 V in 200 ms, 7 of 10 samples, Type B; the 2019 battery energy control module uses its adjacent-cell, balancing and splice tests within 0.6 s, Type A. Ford's Fusion plug-in hybrid bulletin for 2019-2020 includes P0B72 and replaces the traction battery.
P0B72 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor0.5 to 8 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0B72
- No start or no ready mode
- Battery or hybrid system warning
- Charging aborted
Common causes of P0B72
- Most likelyOpen sense lead, crimp or cell tap on channel L
- PossibleInternal traction battery failure, pack replacement (Ford Fusion PHEV)
- Less likelyHigh-resistance splice or bus bar joint
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Hv battery voltage sense lWiring harnessBms
What each part of P0B72 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| B | Area: hybrid propulsion. |
| 72 | The exact fault in that area. |
What to do next
- Note P0B72 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 P0B72
What does P0B72 mean?
P0B72 means "Hybrid/EV Battery Voltage Sense L Circuit". P0B72 reports an open circuit on voltage sense L, the twelfth channel. It is a generic code, so it means the same on every make.
Is it safe to drive with P0B72?
Drive gently and only to a workshop. With P0B72 the car can go into limp mode (reduced power) to protect itself.
Will P0B72 fail an emissions test?
Yes, it can. P0B72 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 P0B72 to fix?
Difficulty: workshop only. A typical repair takes 0.5 to 8 hours of work. This is a job for a workshop.
Will P0B72 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.