Powertrain, generic (extended)

P2D81 Charging Start Switch Circuit Performance

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

P2D81 is the plausibility code of the charging start switch: the wiring reads as healthy, yet the reported switch behaviour cannot be right. Examples of what a control unit can check are a start request lasting far longer than any real press, a request that appears while no charging connector is plugged in, or a press that never produces the expected change of state. No manufacturer documents P2D81 publicly. CARB asks for rationality checks on inputs where feasible and for them to be stored separately from circuit and range faults, which is why this code stands apart from P2D7F and P2D80. The start switch in Honda's patent only mattered with the connector in place, which shows why plug state is a natural cross-check. Charging by button becomes unreliable or is disabled.

Likely causes

Start button sticking or not returning
Worn switch contacts giving an unclear signal
Connector detection signal wrong, so a valid press seems implausible

Symptoms

  • Start button works only sometimes or not at all
  • Charging message about a switch fault

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–350
Time0.5–2 h

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

Parts involved

charging start switchwiring harness

Related codes

P2D7EP2D82P2D7C

References: law.cornell.edu, patents.google.com.