Powertrain, generic

P0E19 Hybrid/EV Battery Pack Coolant Heater B Control Performance

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P0E19 means heater B is commanded and electrically intact but the expected warming does not follow. No manufacturer documents P0E19 publicly. How such a test works is visible in GM's 2016 Volt, where the battery heater performance code P1EC6 runs once per drive or charge: during an active heat request the pack inlet coolant must gain more than 3 °C within 154.1 s, otherwise a Type B fault is stored; it is skipped while coolant level or inlet temperature sensor codes are active. CARB asks for such a functional check of heating where feasible. Air in the loop, a weak pump, a blocked hose or a failing element are the usual causes, and a wrongly routed valve can send the heat elsewhere. Unlike P0E15 for heater A, this concerns the second heater. P0E16 to P0E18 are its circuit codes.

Likely causes

Air pocket or low coolant level in the battery loop
Heater B element producing too little heat
Weak pump, restricted hose or coolant valve in the wrong position
Inlet coolant temperature sensor reading wrongly

Symptoms

  • Check engine light on
  • Battery stays cold for a long time after a cold start
  • Reduced charging and drive power in winter

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–1,800
Time1–4 h

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

Parts involved

hv battery pack coolant heater bwiring harnessbms

Related codes

P0E16P0E17P0E18P0E15P0C4A

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