P0B89 code meaning
Hybrid/EV Battery Voltage Sense P Circuit High
Powertrain system Generic code P0Bxx codes Check engine light
What P0B89 means
P0B89 covers the opposite case to P0B88: the voltage reported on channel P is above the plausible range. GM's 2012 two-mode hybrids assign P to NiMH block 16 and set the code when the block exceeds 23 V in 15 of 20 samples at 100 ms, Type B, provided no battery controller fault P0A1F is active. In lithium-ion systems GM sets 4.8 V or more for 1.4 s in 2 s as the limit, Type A, while the BAS Plus mild hybrid reacts above 4.65 V. GM's 2016 program with a separate sense module allows up to 4.90 V. Overcharging is unlikely to be the cause because the controller stops charging well below these values; a sense lead reaching a higher tap or an input fault is the usual explanation. Expect restricted charging.
P0B89 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor1 to 8 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0B89
- Charging restricted
- MIL and hybrid warning
Common causes of P0B89
- Most likelyLead P in contact with a higher cell tap
- PossibleInput fault in the cell monitoring electronics
- Less likelyGenuine overvoltage of the cell or block
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 P0B89 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. |
| 89 | The exact fault in that area. |
What to do next
- Note P0B89 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 P0B89
What does P0B89 mean?
P0B89 means "Hybrid/EV Battery Voltage Sense P Circuit High". P0B89 covers the opposite case to P0B88: the voltage reported on channel P is above the plausible range. It is a generic code, so it means the same on every make.
Is it safe to drive with P0B89?
Drive gently and only to a workshop. With P0B89 the car can go into limp mode (reduced power) to protect itself.
Will P0B89 fail an emissions test?
Yes, it can. P0B89 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 P0B89 to fix?
Difficulty: workshop only. A typical repair takes 1 to 8 hours of work. This is a job for a workshop.
Will P0B89 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.