Powertrain, generic (extended)

P2DD1 Control Pilot Charging Switch B Circuit High

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

P2DD1 reports a voltage on the drive or feedback wire of switch B that is higher than it should be. Likely culprits are a wire touching battery voltage or another feed somewhere between inlet and module, or a transistor stage that has lost the ability to pull its output low. Whether the switch then stays open or closed depends on the design. If it stays open, the pilot remains at about 9 V, the J1772 state of a connected vehicle that does not ask for energy, and the station keeps the cable dead. No manufacturer documents P2DD1 publicly; CARB's plug-in rules ask for detection of on-board charger faults that prevent charging. Low side: P2DD0; plausibility: P2DCF; switch A high: P0CFB. Check connectors for moisture and pushed-back pins before replacing the module.

Likely causes

Switch B line shorted to a supply voltage
Driver stage in the charging module no longer pulling low
Moisture or pushed-back pins at inlet or module connector

Symptoms

  • Car stays in plugged-in state, station supplies no power
  • Charging session cannot be ended cleanly

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–1,200
Time0.5–3 h

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

Parts involved

control pilot switch bwiring harnesson board charger

Related codes

P2DD0P2DCEP2DCFP2DD2P0CFB

References: en.wikipedia.org, law.cornell.edu.