What are the common causes of P0E19?

A coolant heater B that does not reach or hold the commanded temperature. A weak heater B element. A blocked or air-locked coolant path through heater B. A heater B control module that misdrives the element.

Command heater B with a scan tool and watch the temperature rise. Check the coolant level and bleed air from the loop. Check the heater B coolant path for flow. Measure the heater B element resistance. Replace the heater B element or module if temperature stays low. Clear the code and retest.

P0E19

Hybrid/EV Battery Pack Coolant Heater B Control Performance

System: Powertrain control (P code)
Lamp: Check Engine Light
Category: Powertrain - Hybrid Propulsion

What it means

P0E19 means Hybrid/EV Battery Pack Coolant Heater B Control Performance.

Check these first

A coolant heater B that does not reach or hold the commanded temperature
A weak heater B element
A blocked or air-locked coolant path through heater B
A heater B control module that misdrives the element

What to do next

Command heater B with a scan tool and watch the temperature rise
Check the coolant level and bleed air from the loop
Check the heater B coolant path for flow
Measure the heater B element resistance
Replace the heater B element or module if temperature stays low
Clear the code and retest

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Updated

Generic SAE J2012 definition. Last updated 2026-10-10.