Open circuit in the coolant heater control wire (broken wire, loose connector, or corroded terminal); Short to voltage on the control circuit (wiring chafed against a power wire); Faulty coolant heater element or heater control module; Failed battery pack coolant temperature sensor providing incorrect feedback; Corrosion or water intrusion in the heater connector; Faulty hybrid/EV control module (less common)

DTC codes / P0Exx · Hybrid propulsion / P0E14

P0E14Hybrid/EV Battery Pack Coolant Heater A Control Circuit High

P0E14 indicates that the hybrid or electric vehicle battery pack coolant heater control circuit is reporting a voltage higher than expected, which the computer detects as an open circuit or a short to voltage on the control wire. The heater is used to warm the battery coolant in cold conditions to improve performance and charging, so this fault may prevent that function from working.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaHybrid propulsion

Symptoms you may notice

Illumination of the check engine light or service vehicle soon message
Often no symptoms besides the warning light
Reduced hybrid/EV performance or charging efficiency in cold weather
Battery pack may remain cold, leading to limited power output
Possible failure of the coolant heater to activate when needed
In some cases, a no-start condition or reduced electric range

Common causes, most likely first

Open circuit in the coolant heater control wire (broken wire, loose connector, or corroded terminal)
Short to voltage on the control circuit (wiring chafed against a power wire)
Faulty coolant heater element or heater control module
Failed battery pack coolant temperature sensor providing incorrect feedback
Corrosion or water intrusion in the heater connector
Faulty hybrid/EV control module (less common)

How to diagnose and fix it

Inspect the coolant heater connector and wiring for damage, corrosion, or loose pins
Check for continuity and resistance on the control circuit between the heater and the control module
Test for short to voltage on the control wire with a multimeter while wiggling the harness
Verify the coolant heater element resistance against specifications
Check the battery pack coolant temperature sensor signal for accuracy
If wiring and sensor are good, test or replace the coolant heater assembly
Clear the code and perform a road test to confirm the repair

Don't overlook the coolant heater relay

A stuck-closed coolant heater relay can feed voltage back into the control circuit, setting this code even when the heater itself is fine.
The code can be set by a poor ground connection at the heater, which causes the control module to see an unexpected voltage on the control wire.
In some vehicles, the coolant heater is only active below a certain ambient temperature, so the fault may not appear until cold weather arrives.
A weak or failing 12-volt auxiliary battery can cause erratic module behavior and false control circuit codes, so always check battery health first.
After replacing the heater, some models require a relearn or calibration procedure for the hybrid control module to recognize the new component.

Can I keep driving with P0E14?

You can generally continue driving, but avoid relying on the vehicle for long trips in cold weather until the fault is repaired, as the battery may not warm properly and performance could be reduced. If the warning light is accompanied by a significant loss of power or charging issues, seek service promptly.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.