P0E9BDC/DC Converter Current Sensor B Circuit
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P0E9B opens the series for the second current measurement of a DC/DC converter, sensor B. It covers a signal that is absent or unusable on the electrical level and that the controller cannot classify as low, high or implausible; those cases follow as P0E9C to P0E9F. No manufacturer documents P0E9B itself. Porsche confirms what sensor B is in practice: on the Taycan the high-voltage power electronics name the same channel current sensor 2 and store its short to ground as P0E9D00. Ford's hybrid summary shows what a current input check looks at, an offset below 15 A at power-up and a raw value kept inside 4.5-6.0 V. CARB makes circuit monitoring of such inputs mandatory. Without the reading the converter usually derates.
- What you may notice
- High-voltage or 12 V system warning
- Converter output reduced, 12 V battery charged less
- Possibly reduced drive power
- Likely causes
- LikelyFault in the converter's internal current sensing
- PossibleConnector or wiring fault on the sensor B path
- RareControl software misjudging the signal
- 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 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.