P0D99Battery Charger Coupler Temperature Sensor A Circuit
- Generic OBD-II code · Powertrain
- How the car detects it
- P0D99 flags a general electrical fault in temperature sensor A of the charging inlet, the element that tells the car how hot the power contacts are. At high current, contact resistance heats the pins; the reading lets the car throttle or stop charging (TE Connectivity, US10960781B2). Inlet suppliers fit resistive sensors: Phoenix Contact strings PTC elements along the AC pins and puts a Pt 1000 on each DC pin, with shutdown above +90 °C at the contact. For the third-generation smart electric drive with 22 kW charger, Mercedes defines P0D9900 as an electrical fault of the inlet contact temperature sensor; bulletin LI54.10-P-067823 traces it, like neighbouring sensor codes, to loose low-voltage plugs at the charger. Without a usable reading, charging is refused or limited. Implausible, low and high readings are P0D9A–P0D9C.
- What you may notice
- High-voltage battery cannot be charged
- Charging only at reduced power
- Charging system fault message
- Likely causes
- LikelyLoose low-voltage connector at the on-board charger (smart)
- PossibleDamaged sensor wiring between inlet and charger
- PossibleTemperature element in the inlet failed (usually replaced with the inlet harness)
- RareEvaluation input in the charger module defective
- Repair
- Medium · Usually a job for a workshop.Typical cost: €50 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.