P0BC1 code meaning
Hybrid/EV Battery Pack Cooling Fan Supply Voltage Circuit High
Powertrain system Generic code P0Bxx codes Check engine light
What P0BC1 means
P0BC1 flags voltage on the battery fan feed when there should be none, or more than expected. GM documents it for the battery pack control module of its Two-Mode hybrid SUVs and pickups (Tahoe, Yukon, Escalade, Silverado, Sierra; 2012 and 2013 tables) as a welded fan relay: with the fan commanded off, a fan monitor voltage of at least 0.9 V in 10 of 20 samples at 100 ms sets it, provided the 12 V system is between 9 and 18 V and no fan circuit code (P0A81) is active. It is Type B, MIL after two trips. A stuck relay keeps the fan running with the vehicle off and drains the 12 V battery. The open and low cases are P0BBF and P0BC0; a fan that keeps turning without this fault is P0A83.
P0BC1 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyEasy, DIY possible
- Typical labor0.2 to 1.5 hours
- Clears after repairAfter a drive cycle
Symptoms of P0BC1
- MIL on after two trips
- Battery fan keeps running after the vehicle is switched off
- Discharged 12 V battery after standing
Common causes of P0BC1
- Most likelyFan relay contacts welded closed
- PossibleFan feed shorted to a constant battery voltage wire
- Less likelyRelay control output in the module stuck on
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Hv battery cooling fan supplyBattery cooling fan relayWiring harnessBms
What each part of P0BC1 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. |
| C1 | The exact fault in that area. |
What to do next
- Note P0BC1 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 P0BC1
What does P0BC1 mean?
P0BC1 means "Hybrid/EV Battery Pack Cooling Fan Supply Voltage Circuit High". P0BC1 flags voltage on the battery fan feed when there should be none, or more than expected. It is a generic code, so it means the same on every make.
Is it safe to drive with P0BC1?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P0BC1 fail an emissions test?
Yes, it can. P0BC1 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 P0BC1 to fix?
Difficulty: easy. A typical repair takes 0.2 to 1.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P0BC1 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.