A faulty temperature sensor D itself, with an internal intermittent connection or failing thermistor element; Damaged, chafed, or corroded wiring in the sensor circuit, often near the battery pack connector or where the harness bends; Loose or contaminated electrical connector pins at the sensor or at the battery energy control module; A failing battery energy control module, though this is less common than sensor or wiring faults; Moisture intrusion into the sensor connector or harness, causing erratic resistance readings; Heat damage or vibration fatigue affecting the sensor or its wiring over time

DTC codes / P0Axx · Hybrid propulsion / P0AEC

P0AECHybrid/EV Battery Temperature Sensor D Circuit Intermittent/Erratic

P0AEC means the hybrid or electric vehicle battery pack's temperature sensor D is sending an intermittent or erratic signal to the battery energy control module. The computer has detected that the sensor's voltage or resistance reading jumps around or drops out unpredictably, rather than staying within a stable expected range.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyProfessional

AreaHybrid propulsion

Symptoms you may notice

Illumination of the hybrid system warning light or check engine light
Often no symptoms besides the warning light, especially in mild weather
Reduced electric-only driving range or forced engine operation in a hybrid
A message on the dash advising that hybrid or EV service is required
In rare cases, limited power output or a forced limp mode if the fault escalates
Inconsistent battery cooling fan operation or unusual fan noise

Common causes, most likely first

A faulty temperature sensor D itself, with an internal intermittent connection or failing thermistor element
Damaged, chafed, or corroded wiring in the sensor circuit, often near the battery pack connector or where the harness bends
Loose or contaminated electrical connector pins at the sensor or at the battery energy control module
A failing battery energy control module, though this is less common than sensor or wiring faults
Moisture intrusion into the sensor connector or harness, causing erratic resistance readings
Heat damage or vibration fatigue affecting the sensor or its wiring over time

How to diagnose and fix it

Scan all hybrid and battery control modules for stored and pending codes, and record freeze-frame data to see when the intermittent fault occurs
Inspect the sensor D wiring and connector for chafing, corrosion, moisture, or loose pins, and repair as needed
Back-probe the sensor signal circuit at the battery energy control module and wiggle-test the harness while watching live temperature data for dropouts
Measure the resistance of sensor D at known temperatures and compare it to the manufacturer's temperature-resistance chart to confirm sensor accuracy
If the sensor is accessible, substitute it with a known-good sensor or a resistor of the correct value to see whether the erratic reading disappears
Check for technical service bulletins or software updates for the battery energy control module that address temperature sensor signal processing
Replace the faulty temperature sensor or the affected section of harness, then clear codes and verify that live data remains stable during a road test

What intermittent sensor codes really mean

An intermittent temperature sensor code often appears only during certain driving conditions, such as after a cold soak or when the battery pack is under heavy load, so a static test may show nothing wrong.
A common misdiagnosis is replacing the battery pack itself when the actual fault is a chafed wire or a corroded connector pin that costs far less to repair.
The battery energy control module may set this code based on a rationality check against other temperature sensors, so a sensor that reads plausibly but drifts can still trigger it.
High-voltage battery cooling system faults, such as a failing fan or blocked duct, can cause temperature readings to swing and set an intermittent sensor code even when the sensor is good.
After any repair, the code may remain stored until several drive cycles complete, so technicians should not assume the fix failed if the light stays on briefly.

Can I keep driving with P0AEC?

You can usually continue driving with this code because the fault is intermittent and the battery management system often has safeguards, but avoid aggressive acceleration, sustained high speeds, and extreme temperatures until it is diagnosed. If the hybrid system warning light flashes or power is reduced, have the vehicle checked 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.