P0B74 code meaning
Hybrid/EV Battery Voltage Sense L Circuit Low
Powertrain system Generic code P0Bxx codes Check engine light
What P0B74 means
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.
P0B74 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 P0B74
- MIL and hybrid system warning
- Electric operation restricted
- Engine runs continuously on hybrids
Common causes of P0B74
- Most likelyChannel L sense lead shorted to a lower potential
- PossibleDefective measuring input in the battery controller
- Less likelyCell or block on channel L actually failed
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 P0B74 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. |
| 74 | The exact fault in that area. |
What to do next
- Note P0B74 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 P0B74
What does P0B74 mean?
P0B74 means "Hybrid/EV Battery Voltage Sense L Circuit Low". P0B74 is set when channel L reads implausibly low. It is a generic code, so it means the same on every make.
Is it safe to drive with P0B74?
Drive gently and only to a workshop. With P0B74 the car can go into limp mode (reduced power) to protect itself.
Will P0B74 fail an emissions test?
Yes, it can. P0B74 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 P0B74 to fix?
Difficulty: workshop only. A typical repair takes 1 to 8 hours of work. This is a job for a workshop.
Will P0B74 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.