Powertrain, generic (extended)

P2D71 Battery Charging System Negative Contactor D Stuck Closed

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

P2D71 indicates that negative charging contactor D has stayed closed after an open command, as happens when the contacts fuse. No manufacturer documents P2D71 publicly. A Toyota patent addresses a pitfall of this check: after DC charging the car asks the station to stop, but some stations keep feeding, and the leftover inlet voltage would wrongly suggest welded relays. Toyota therefore repeats a suspicious result after opening the main relays and draining the capacitor, then opens one charge relay at a time against a threshold of a few to a few tens of volts. A Ford patent adds the consequence: one weld locks charging, a weld on both poles also stops the car from driving. P2D72 is the opposite fault, P2D6A the plus side.

Likely causes

Fused contacts in minus contactor D
Station kept supplying voltage during the check
Coil held on by a faulty output stage

Symptoms

  • Charging locked after a DC session
  • Vehicle may refuse to become ready if the plus side is welded as well
  • High-voltage warning at start-up

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 neg contactor dwiring harnessbms

Related codes

P2D70P2D72P2D6AP2D63P2BCCP0D0F

References: patents.google.com, patents.google.com.