Powertrain, generic · Hybrid propulsion

P0D9D Battery Charger Coupler Temperature Sensor A Circuit Intermittent/Erratic

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

P0D9D is logged when the signal of temperature sensor A in the charging inlet jumps or drops out for short moments instead of failing for good. The sensor sits beside the power pins so the car can cut back or end charging once contact resistance heats them; TE Connectivity patents US10960781B2 and US11117478B2 name thermistors and resistance thermometers for this job. No manufacturer documents P0D9D publicly. A related smart case shows the pattern: with the 22 kW charger, Mercedes blamed inlet sensor codes on loose low-voltage plugs at the charger and warned that the fault may only show up with warm or cold parts. Typical is a session that stops for no clear reason and works again later. Steady circuit, plausibility, low and high faults are P0D99 to P0D9C.

Likely causes

Sensor wiring between inlet and charger with a loose or chafed contact
Low-voltage connector at the on-board charger not fully seated (seen on smart for sibling codes)
Moisture or corrosion in the inlet harness connector
Temperature element in the inlet with an internal intermittent break

Symptoms

  • Charging stops now and then and resumes on a later attempt
  • Charging power reduced for a while without an obvious reason
  • Charging fault message that comes and goes

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–1,200
Time0.5–4 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

charge port temperature sensorwiring harnesson board charger

Related codes

P0D99P0D9AP0D9BP0D9CP0E5F

References: patents.google.com, patents.google.com, static.nhtsa.gov, law.cornell.edu.