Powertrain, generic · Hybrid propulsion
P0A85 Hybrid/EV Battery Pack Cooling Fan 1 Control Circuit High
Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible
The controller detects a short to voltage on the control output of battery cooling fan 1. GM runs the test while the fan is commanded between 11 % and 100 % duty: a circuit voltage above 9 V counts as a failure, and 16 fails in 20 samples set a Type B code with MIL after two trips. GM tables from 2013, 2016, 2018 and 2019 hybrid programs carry it, partly via the output stage status flag. Depending on the circuit, the fan may run constantly at full speed or not respond. The low and open counterparts are P0A84 and P0A81; a fan that keeps running without a circuit fault is P0A83.
Likely causes
Control wire shorted to a supply voltage
Fan control input internally open or shorted to its supply
Corroded connector creating leakage to supply
Symptoms
- Check engine or hybrid warning after two trips
- Battery fan runs constantly or not at all
- Possible 12 V battery drain when parked
Repair estimate
DifficultyMediumWorkshop job
Parts and labour€60–700
Time0.5–3 h
Typical range across vehicles; the real cost depends on what the testing finds.
Parts involved
hybrid battery cooling fan 1wiring harnessbms
Related codes
References: gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com.