P0D99 code meaning
Battery Charger Coupler Temperature Sensor A Circuit
What P0D99 means
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.
P0D99 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0D99
- High-voltage battery cannot be charged
- Charging only at reduced power
- Charging system fault message
Common causes of P0D99
- Most 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)
- Less likelyEvaluation input in the charger module defective
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Charge port temperature sensorWiring harnessOn board charger
What each part of P0D99 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 99 | The exact fault in that area. |
What to do next
- Note P0D99 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 P0D99
What does P0D99 mean?
P0D99 means "Battery Charger Coupler Temperature Sensor A Circuit". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P0D99?
P0D99 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will P0D99 fail an emissions test?
P0D99 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is P0D99 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P0D99 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.