Powertrain, generic · Hybrid propulsion

P0AD2 Hybrid/EV Battery Pack Cooling Fan 3 Control Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0AD2 reports that the control signal for battery fan 3 is pulled too low, typically a short to ground on the line between battery controller and blower. Such fans are mostly speed-controlled by a PWM duty cycle, as a Toyota patent on battery fan control explains. No manufacturer publicly documents P0AD2; GM sets the analogous fan 1 code P0A84 when the control voltage stays below 0.257 V with system voltage above 9.1 V, Type B with two trips. The open circuit is P0ACF, a short to voltage P0AD3. CARB requires these electrical checks for battery thermal components. Fan 3 then cannot be driven, and the battery may run warm with limited power.

Likely causes

Control wire chafed through to body ground
Internal short in fan 3 motor or its electronics
Moisture or spilled liquid in the fan connector
Output stage in the battery controller defective

Symptoms

  • Hybrid or EV system warning light, often with check engine light
  • Electric drive power reduced when the battery gets warm
  • No fan noise from the battery area when cooling is expected

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–600
Time0.5–3 h

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

Parts involved

hv battery cooling fan 3wiring harnessbms

Related codes

P0ACFP0AD3P0AD0P0A84P0A99

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