P0B89Hybrid/EV Battery Voltage Sense P Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- 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.
- What you may notice
- Charging restricted
- MIL and hybrid warning
- Likely causes
- LikelyLead P in contact with a higher cell tap
- PossibleInput fault in the cell monitoring electronics
- RareGenuine overvoltage of the cell or block
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €100 – €6,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.