Powertrain, generic (extended)

P2D64 Battery Charging System Negative Contactor C Stuck Open

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

P2D64 appears when minus charging contactor C does not close; the third charging path then lacks its return conductor and no current flows even with the plus contactor in. No manufacturer documents P2D64 publicly. The principle mirrors GM's Volt check of plus contactor A (P0D09): once charge and precharge contactors are commanded closed, charger-side voltage should rise, and under 10 V in 8 of 9 readings fails the test. Seen from outside, a missing minus connection looks just like a missing plus one, so telling P2D64 from P2D5D needs both coil drives to be checked. CARB requires charger faults that prevent charging to be detected on plug-in hybrids. Burnt contacts, a weak coil feed and software are typical. P2D63 is the welded variant.

Likely causes

Minus contactor C does not pull in or contacts burnt
Weak coil supply from wiring or connector faults
Software misreads the precharge result

Symptoms

  • Charging in the affected mode never starts
  • Charging station aborts immediately
  • Driving unaffected

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€150–4,000
Time1–10 h

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

Parts involved

bcs neg contactor cwiring harnessbms

Related codes

P2D62P2D63P2D65P2D5DP2BCDP0D10

References: gsi.ext.gm.com, law.cornell.edu.