P0B87 code meaning
Hybrid/EV Battery Voltage Sense P Circuit Range/Performance
Powertrain system Generic code P0Bxx codes Check engine light
What P0B87 means
P0B87 says channel P is delivering numbers that do not fit the rest of the battery. On GM's BAS Plus mild hybrid the cell under test must move at least 50 percent as far as the average cell voltage; if not, 20 failures in 40 samples set the code as Type B, i.e. MIL after two trips. GM's 2019 lithium-ion processor is stricter in its rating, Type A after 35 of 40 samples, and looks for a value that stays flat by less than 0.005 V while the average moves more than 0.022 V. The 2012 two-mode trucks check NiMH block 16, together with block 17, against the pack voltage with a 70 V window, 160 of 170 samples, Type B. Since wiring faults have their own codes (P0B86, P0B88, P0B89), this one points towards measuring electronics or software.
P0B87 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor0.5 to 6 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0B87
- MIL after two trips on Type B systems
- Engine start-stop or electric assist less frequent
Common causes of P0B87
- Most likelyMeasuring electronics for channel P out of tolerance
- PossibleSoftware or calibration of the battery controller
- Less likelyNiMH block 16 or 17 out of balance with the pack
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 pWiring harnessBms
What each part of P0B87 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. |
| 87 | The exact fault in that area. |
What to do next
- Note P0B87 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 P0B87
What does P0B87 mean?
P0B87 means "Hybrid/EV Battery Voltage Sense P Circuit Range/Performance". P0B87 says channel P is delivering numbers that do not fit the rest of the battery. It is a generic code, so it means the same on every make.
Is it safe to drive with P0B87?
Drive gently and only to a workshop. With P0B87 the car can go into limp mode (reduced power) to protect itself.
Will P0B87 fail an emissions test?
Yes, it can. P0B87 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 P0B87 to fix?
Difficulty: workshop only. A typical repair takes 0.5 to 6 hours of work. This is a job for a workshop.
Will P0B87 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.