P00FDBattery B State of Charge Performance
- Generic OBD-II code · Powertrain
- How the car detects it
- 'Battery B' here is not a hybrid high-voltage battery (those have codes from P0B27) but, in the only documented use by FCA/Stellantis, the 12 V auxiliary battery of the start-stop system. When the engine restarts automatically, a relay separates main and auxiliary battery so that the auxiliary one keeps the control units stable while the main battery cranks. The engine module sets P00FD if the auxiliary battery is disconnected on the first start, drops below about 8 V during an auto-start, or repeatedly falls below 10.3 V (counter reaches ten). Start-stop is then disabled; often it follows a jump start or many short trips. Whether the MIL comes on is not stated in the sources.
- What you may notice
- Start-stop out of service, 'Service Start/Stop' message
- Engine does not crank once
- 'Service Shifter' message with electronic gear selector
- Likely causes
- LikelyAuxiliary battery discharged or aged
- LikelyLoose or corroded positive or ground connections at either battery
- Possible150 A fuse or fuse array in the power distribution centre open or poorly contacting
- RareBattery separation relay stuck
- RareMain battery faulty
- Repair
- Easy · Often possible to do yourself.Typical cost: €0 – €250
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.