Damaged, chafed or shorted wiring in the control pilot or ventilation switch circuit; Corroded, bent or loose terminals at the charge inlet or control unit connector; Water or dirt contamination in the charge inlet or switch assembly; Faulty ventilation switch or charge inlet assembly; Faulty charge point or charging cable sending an incorrect pilot signal; Faulty on-board charger or charging control unit; Outdated control unit software where the manufacturer has issued a fix.

P0D02

Control Pilot Charging Ventilation Switch Circuit Low.

Generic
Powertrain
Generic code
Medium severity

How this code is built

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

What it means

P0D02 is set when the charging control unit sees the control pilot charging ventilation switch circuit voltage or signal below the expected range. The control pilot is the signalling line between the charge point and the vehicle during plug-in charging, and the ventilation switch input tells the vehicle whether charging needs ventilation. The exact circuit layout and monitoring thresholds depend on the model.

Symptoms

Vehicle will not start charging or stops charging early
Charging fault or warning message on the dash
Charge port indicator light flashing or showing a fault
Malfunction indicator or hybrid/EV system warning light on
Charging works on some charge points but not others

Possible causes

Damaged, chafed or shorted wiring in the control pilot or ventilation switch circuitlikely
Corroded, bent or loose terminals at the charge inlet or control unit connectorlikely
Water or dirt contamination in the charge inlet or switch assemblypossible
Faulty ventilation switch or charge inlet assemblypossible
Faulty charge point or charging cable sending an incorrect pilot signalpossible
Faulty on-board charger or charging control unitrare
Outdated control unit software where the manufacturer has issued a fixrare

How to diagnose

Read the stored codes and freeze frame data, noting whether the fault is current or intermittent, and record any other charging or hybrid system codes.
Try a different charge point and charging cable to rule out an external fault.
Visually inspect the charge inlet for water, debris, burnt or damaged pins and a damaged flap or seal.
Inspect the wiring and connectors between the charge inlet and the charging control unit for chafing, corrosion, pushed-out pins and water ingress.
Check the manufacturer's wiring information for the circuit layout, then measure the signal voltage at the control unit against specification, following the high-voltage safety procedure for the vehicle.
Check the ventilation switch input and circuit for a short to earth or low resistance, with the system safely isolated as the manufacturer requires.
Check for technical bulletins or software updates relating to charging faults on that model.
Clear the code and retest charging to confirm whether the fault returns.

How to fix

Repair or replace damaged wiring and restore the circuit to the manufacturer's specification.
Clean or replace corroded connectors and terminals, and ensure they are properly seated and sealed.
Dry out and clean the charge inlet, or replace it if water damage or pin damage is found.
Replace the faulty ventilation switch or charge inlet assembly if it tests out of specification.
Replace the charging control unit or on-board charger only after wiring and inlet faults are ruled out.
Update the control unit software if an approved update addresses this fault.

Can I keep driving?

Medium severity

The car can usually still be driven, but charging may be unavailable, so a pure EV could leave you stranded with a low battery. Get it checked soon, and have any high-voltage work done by a suitably trained technician.

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