Open or chafed signal wire between sensor D and the battery control module; Corroded, loose, or water-intruded connector at the sensor or module; Failed coolant temperature sensor D (open thermistor element); High resistance in the sensor ground circuit shared with other sensors; Coolant contamination or low coolant level affecting sensor immersion; Internal fault in the battery control module or its sensor reference voltage supply; Rodent damage or pinched harness along the battery pack coolant line routing

DTC codes / P2Exx · Hybrid propulsion / P2E76

P2E76Hybrid/EV Battery Pack Coolant Temperature Sensor D Circuit Low

P2E76 means the hybrid or electric vehicle battery pack coolant temperature sensor D circuit is reporting a voltage below the normal range, so the battery control module cannot trust that sensor's reading. The computer detected a low-voltage condition on the signal circuit, which usually points to a wiring fault, a poor connection, or a failed sensor rather than an actual overheating event.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyProfessional

AreaHybrid propulsion

Symptoms you may notice

Illuminated check engine light or hybrid system warning light, often with no other symptoms
Reduced electric-only driving range or the vehicle refusing to enter EV mode
Battery cooling fan running continuously or at unusually high speed
Powertrain power limitation or turtle mode in severe cases
Inconsistent state-of-charge readings or unexpected engine starts in a plug-in hybrid
No noticeable drivability change in many instances besides the warning light

Common causes, most likely first

Open or chafed signal wire between sensor D and the battery control module
Corroded, loose, or water-intruded connector at the sensor or module
Failed coolant temperature sensor D (open thermistor element)
High resistance in the sensor ground circuit shared with other sensors
Coolant contamination or low coolant level affecting sensor immersion
Internal fault in the battery control module or its sensor reference voltage supply
Rodent damage or pinched harness along the battery pack coolant line routing

How to diagnose and fix it

Scan all modules and record freeze-frame data for P2E76 plus any companion codes before clearing anything
Inspect the sensor D connector and harness for corrosion, water intrusion, chafing, and rodent damage
Measure sensor resistance at the connector and compare it to the manufacturer's temperature-resistance chart
Backprobe the signal circuit to check for a short to ground or an open circuit while wiggling the harness
Verify the sensor reference voltage and ground circuit integrity at the battery control module connector
Replace the coolant temperature sensor D if resistance testing confirms an open or out-of-range element
Clear codes, perform a battery pack coolant temperature rationality test, and road-test to confirm the repair

What P2E76 does not always mean

A low-voltage signal on sensor D frequently comes from a connector that has been contaminated by coolant seepage rather than from a failed sensor, so inspect the plug before condemning the part.
Technicians sometimes replace the battery pack coolant temperature sensor when the real fault is a shared ground circuit that also affects other sensors, which is why checking ground integrity at the module is essential.
P2E76 can set intermittently after a battery pack coolant service if air is trapped around the sensor, so a proper bleed and level check should precede any parts replacement.
The code does not confirm the battery is overheating; it only reports an electrical circuit fault, and the pack may be at a perfectly normal temperature.
On some platforms the battery control module must be reflashed or initialized after sensor replacement, and skipping that step can leave the code stored even with a good sensor.

Can I keep driving with P2E76?

You can usually drive the vehicle short distances to a repair shop, but avoid sustained high-speed driving, rapid charging, and heavy loads until the fault is repaired because the battery cooling strategy may be compromised. If the vehicle enters a power-limited mode or shows a red battery warning, stop driving and arrange a tow.

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.