P0B74Hybrid/EV Battery Voltage Sense L Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P0B74 is set when channel L reads implausibly low. On the 2012 GM two-mode hybrids, where L is nickel-metal hydride block 12 of 20, the battery pack control module needs both block 12 and block 13 under 2 V in 15 of 20 samples before it stores the code as Type B; no battery control module fault P0A1F may be active. For lithium-ion packs GM's 2016 and 2019 tables use 0.2 V or less for 1.4 s within 2 s, Type A, and the BAS Plus mild hybrid 1.4 V in 7 of 10 samples, Type B. A short of the sense lead to a lower potential, a defective monitoring input or, more rarely, a cell that has really collapsed are the candidates. The vehicle will normally restrict electric operation.
- What you may notice
- MIL and hybrid system warning
- Electric operation restricted
- Engine runs continuously on hybrids
- Likely causes
- LikelyChannel L sense lead shorted to a lower potential
- PossibleDefective measuring input in the battery controller
- RareCell or block on channel L actually failed
- 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.