Powertrain, generic (extended)

P2DD0 Control Pilot Charging Switch B Circuit Low

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

P2DD0 says the drive or sense wire of switch B reads below its valid range. The usual reasons are a wire chafed through to body ground or a shorted transistor stage in the charging electronics. Depending on how the switch is driven, a grounded line can hold it permanently closed, so the pilot stays at the charge-request level of about 6 V, or keep it from ever closing. CARB requires plug-in hybrids to recognise charger faults that block or limit charging, but exempts failures that cannot be told apart from problems at the station; a short inside the vehicle is clearly on the car side. No manufacturer documents P2DD0 publicly. Owners may see charging begin as soon as the cable is connected, or not at all. High: P2DD1; open: P2DCE; switch A low: P0CFA.

Likely causes

Switch B wire chafed and shorted to ground
Output stage in the charging module failed shorted
Moisture in the charge inlet creating a leakage path

Symptoms

  • Charging starts immediately on plug-in or not at all
  • Timed charging not followed
  • Charging fault message

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

P2DD1P2DCEP2DCFP2DD2P0CFA

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