Damaged, corroded or contaminated terminals or connector at the charge inlet or sensor; Faulty coupler temperature sensor (open or shorted internally); Wiring fault between the sensor and the charging control unit (open circuit, short to earth or short to supply, chafing); Water ingress or physical damage to the charge inlet assembly; Fault in the on-board charger or charging control unit; Outdated control unit software where the manufacturer has issued a known fix.

P0D99

Battery Charger Coupler Temperature Sensor A Circuit.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
D: AreaReserved
99: FaultThe specific fault in that area

What it means

P0D99 is a generic powertrain code relating to the Battery Charger Coupler Temperature Sensor A circuit, found on plug-in hybrid and electric vehicles. The charging control unit monitors the signal from a temperature sensor at the charge coupler (the inlet or connector area). It set the code because the sensor signal was outside the expected range or implausible, which points to a circuit fault or a sensor fault. The exact sensor location and the way the fault is classed (high, low, range or performance) depend on the model.

Symptoms

Charge warning light or hybrid/EV system warning on the dashboard
Vehicle will not charge, or charging stops part way through
Charging is slower than normal because current is limited
Charge port locking or charge indicator behaving oddly
Fault code stored with no other obvious driveability change

Possible causes

Damaged, corroded or contaminated terminals or connector at the charge inlet or sensorlikely
Faulty coupler temperature sensor (open or shorted internally)likely
Wiring fault between the sensor and the charging control unit (open circuit, short to earth or short to supply, chafing)possible
Water ingress or physical damage to the charge inlet assemblypossible
Fault in the on-board charger or charging control unitrare
Outdated control unit software where the manufacturer has issued a known fixrare

How to diagnose

Read all stored and pending codes and note any other charging or high-voltage codes, then review the freeze frame data.
Inspect the charge inlet and coupler visually for damage, burn marks, debris, moisture or bent or corroded pins, following the manufacturer's high-voltage safety guidance.
Check live data for the coupler temperature reading and compare it with ambient temperature on a cold vehicle; a fixed, extreme or erratic value indicates a sensor or circuit fault.
Inspect the sensor wiring and connectors for chafing, pin tension, corrosion and water ingress.
With the circuit isolated and in line with the manufacturer's procedure, test the wiring for continuity, short to earth and short to supply.
Measure the sensor resistance and compare it with the manufacturer's specification at a known temperature.
Check for technical service bulletins or software updates for the charging system on that model.
Only if the sensor and wiring are proven good, investigate the charging control unit.

How to fix

Clean or repair the connector and terminals, and replace any that are corroded or damaged.
Repair or replace damaged wiring between the sensor and the control unit.
Replace the coupler temperature sensor, or the charge inlet assembly if the sensor is not supplied separately.
Dry out and seal or replace the inlet assembly after water ingress, and correct the cause of the leak.
Update the control unit software if a known fault is documented, or repair or replace the charging control unit if it is proven faulty.
Clear the code after the repair and complete a full charge cycle to confirm it does not return.

Can I keep driving?

Medium severity

The car can usually be driven, but charging may be limited or unavailable, so get it checked soon. Do not keep using a charge inlet that shows heat damage, burning or water ingress.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.