Powertrain, generic · Hybrid propulsion

P0AE6 Hybrid/EV Battery Precharge Contactor A Control Circuit Low

Check engine lightOn

EmissionsRelevant

Drive cycleNot required

Limp modePossible

P0AE6 means the control line of precharge contactor A is pulled too low, usually a short to ground. GM documents it in several programs. The 2016 and 2019 hybrid tables test the high-side driver while the contactor is commanded on and fail it below 5.35 V, 13 of 16 samples at 12.5 ms, Type B with two trips, enabled above 10.2 V system voltage. GM's 2013 eAssist battery controller uses a low-side driver and flags low voltage in the off state, which there points to a short to ground or an open circuit, 3 of 5 samples at 50 ms, Type B. CARB requires such circuit checks on hybrid outputs. Because the coil cannot pull in, precharge never starts; the positive main contactor equivalent is P0ADB.

Likely causes

Control wire chafed and shorted to ground

Precharge contactor coil shorted internally

Open circuit on low-side driven designs (GM eAssist)

Driver stage in the battery controller defective

Symptoms

Vehicle does not become ready to drive
MIL and hybrid warning on
Engine start or electric drive unavailable

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 precharge contactor awiring harnessbms

Related codes

P0AE7 P0AE4 P0AE5 P0ADB P0ADF

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