Powertrain, generic · Hybrid propulsion

P0AD4 Hybrid/EV Battery Pack Air Flow System Insufficient Air Flow

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0AD4 is a system-level check of air-cooled traction batteries: the controller concludes that too little air passes the cells, for example because the cell temperatures rise faster than the commanded fan level allows, as a Honda fan diagnosis patent describes. CARB 1968.2 asks for a functional check of the battery cooling performance where feasible. Stellantis lists P0AD4 for the 48 V eTorque battery of the Ram 1500 (TSBs 08-033/034/035-24, 2022-24) and cures some cases with a battery pack control module software update. Unlike the fan circuit codes, P0AD4 is often caused by a blocked intake or duct. Expect a warning lamp and limited assist or electric power.

Likely causes

Cabin air intake grille or duct of the battery blocked (bags, clothing, dust, pet hair)
Battery air filter clogged, where fitted
Battery fan running too slowly
Battery controller software sets the code falsely (Ram eTorque, fixed by update)

Symptoms

  • Check engine or hybrid warning light
  • Reduced electric assist or start-stop not available
  • Battery fan runs loud for long periods

Repair estimate

DifficultyEasyDIY possible
Parts and labour€0–400
Time0.3–2 h

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

Parts involved

hv battery pack air flow systemhv battery cooling fans

Related codes

P0AD0P0AD5P0AD6P0A82P0A97

References: law.cornell.edu, static.nhtsa.gov, patents.google.com.