P0BBFHybrid/EV Battery Pack Cooling Fan Supply Voltage Circuit/Open
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- Air-cooled hybrid packs draw cooling air through a 12 V blower that is fed through a fuse and often a relay; the controller watches the voltage reaching the fan, and Toyota even uses that measured supply voltage to correct the fan duty. P0BBF means this feed is open or missing while the fan should be powered. No manufacturer documents this exact code publicly; GM's Two-Mode hybrid monitors the same feed but reports only the high case, a welded relay, as P0BC1. CARB requires the electrical inputs and outputs of battery thermal management to be monitored. Low and high faults are P0BC0 and P0BC1, faults in the fan's own control line P0A81 to P0A85. Without power the fan stops, the pack warms up and the controller limits power.
- What you may notice
- Hybrid system warning or MIL on
- Battery fan silent when it should run
- Reduced electric assist in hot weather or under load
- Likely causes
- LikelyBlown fuse in the battery fan feed
- PossibleFan relay contacts not closing or relay coil open
- PossibleOpen supply wire or loose terminal at the fan connector
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €10 – €400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.