Powertrain, generic (extended)

P2D6A Battery Charging System Positive Contactor D Stuck Closed

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

P2D6A reports that positive charging contactor D still conducts after being told to open, nearly always because its contacts have welded. No manufacturer documents P2D6A publicly. A Ford patent explains where welds come from and how they are found: of the two charge contactors, the one closing last completes the circuit and takes the arcing, so Ford alternates the closing order between sessions. After charging, that last one is opened first and, once the charger-side voltage has had time to decay, is judged welded if that voltage still roughly equals the battery voltage. A single weld ends charging until repair; with both poles welded the car will not drive either. P2D6B is the opposite fault, P2D71 the minus side, P2D5C the C twin.

Likely causes

Contacts of plus contactor D welded by arcing
Coil kept energised by a faulty output stage
Faulty charger-side voltage measurement simulating a weld

Symptoms

  • Charging locked after the previous session
  • Vehicle may not become ready if the other pole is welded too
  • Fault appears at the end of a charging session

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€200–4,000
Time1–10 h

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

Parts involved

bcs pos contactor dwiring harnessbms

Related codes

P2D69P2D6BP2D71P2D5CP2BC5P0D08

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