Powertrain, generic (extended)

P2D73 Battery Charging System Negative Contactor D Control Circuit/Open

Check engine lightUsually off

EmissionsNot relevant

Drive cycleNot required

Limp modeNo

P2D73 concerns the coil drive of negative charging contactor D: commanded and measured state of the line differ, pointing to an open wire, terminal or winding. No manufacturer documents P2D73 publicly. GM's test for the minus charge contactor (P0D11) is the direct analogue. In the 2016 tables it shares one entry with the plus contactor test and adds a current check: under 57 mA with the driver on means open, as does more than 4 V with it off. The 2011 Volt version only looked at the off state, with a 2 V limit. Both need 40 bad samples of 50 and cannot detect a ground short. The return pole of path D stays open. P2D74–P2D76 are the other drive faults, P2D6C the plus side, P2D65 contactor C.

Likely causes

Open coil drive wire or loose terminal

Broken winding in minus contactor D

Defective driver or current sensing in the module

Symptoms

Charging mode via contactor D not available
Code present at every key-on
Charging fault message

Repair estimate

DifficultyShop_onlyWorkshop job

Parts and labour€100–1,500

Time1–5 h

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

Parts involved

bcs neg contactor dwiring harnessbms

References: gsi.ext.gm.com, gsi.ext.gm.com.