Powertrain, generic · Hybrid propulsion

P0ADC Hybrid/EV Battery Positive Contactor Control Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0ADC indicates that the positive contactor drive circuit carries too much voltage for the commanded state, usually a short to battery voltage. In GM's 2016-19 hybrid tables the driver output, with the contactor commanded off, reads between 5.27 and 19.7 V for 40 of 50 samples at 12.5 ms, Type B with two trips. The 2013 eAssist controller sets it for a short to power on the low-side driver in the on state, 3 of 5 samples. CARB requires such circuit monitoring for hybrid components. Siblings are P0AD9 (open) and P0ADB (low). A short to power can energize the coil unintentionally, so the contactor may not open when it should.

Likely causes

Coil control wire shorted to 12 V
Damaged harness or connector at the battery disconnect unit
Driver stage in the battery controller shorted

Symptoms

  • Hybrid or EV warning light
  • High-voltage system disabled, vehicle not ready
  • Possible related stuck-closed codes

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€100–2,500
Time1–5 h

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

Parts involved

hv battery pos contactorwiring harnessbms

Related codes

P0AD9P0ADAP0ADBP0AE0P0AA1

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