Faulty battery charger voltage sensor or its internal circuitry; Damaged, chafed, or corroded wiring in the sensor circuit, including the signal, ground, or reference voltage wires; Loose or corroded connector pins at the sensor or at the charger assembly; Failed auxiliary battery charger module or its internal power supply; Software calibration issue in the control module that interprets the sensor signal; High resistance in a ground connection shared by the sensor and charger; Extreme ambient temperature affecting sensor accuracy, though this is less common

DTC codes / P0Exx · Hybrid propulsion / P0E86

P0E86Battery Charger B Voltage Sensor Circuit Range/Performance

Q: What does code P0E86 mean?

Battery Charger B Voltage Sensor Circuit Range/Performance. P0E86 indicates that the powertrain control module has detected an out-of-range or erratic signal from the voltage sensor circuit that monitors the auxiliary battery charger, which is often part of the high-voltage system on hybrid and electric vehicles. The computer compares the sensor's reported voltage against expected values and flags the code when the signal falls outside a calibrated window or fails a rationality check.

P0E86 indicates that the powertrain control module has detected an out-of-range or erratic signal from the voltage sensor circuit that monitors the auxiliary battery charger, which is often part of the high-voltage system on hybrid and electric vehicles. The computer compares the sensor's reported voltage against expected values and flags the code when the signal falls outside a calibrated window or fails a rationality check.

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, especially if the charger continues to function normally
Reduced or disabled charging of the auxiliary battery, leading to a low-voltage condition over time
Electrical accessories dimming or behaving erratically due to unstable auxiliary battery voltage
A no-start condition if the auxiliary battery is not being replenished while the vehicle is off
Possible entry into a reduced-power or limp mode if the fault affects high-voltage system readiness

Common causes, most likely first

Faulty battery charger voltage sensor or its internal circuitry
Damaged, chafed, or corroded wiring in the sensor circuit, including the signal, ground, or reference voltage wires
Loose or corroded connector pins at the sensor or at the charger assembly
Failed auxiliary battery charger module or its internal power supply
Software calibration issue in the control module that interprets the sensor signal
High resistance in a ground connection shared by the sensor and charger
Extreme ambient temperature affecting sensor accuracy, though this is less common

How to diagnose and fix it

Use a scan tool to retrieve all stored codes and freeze-frame data, then clear the code and verify whether it returns immediately or after a drive cycle
Visually inspect the battery charger voltage sensor, its connector, and the wiring harness for damage, corrosion, or loose pins
Measure the sensor reference voltage and ground at the sensor connector with a digital multimeter and compare to manufacturer specifications
Back-probe the sensor signal wire and monitor voltage while wiggling the harness to detect intermittent faults
Check the auxiliary battery charger module for power and ground, and verify its communication with the control module
If the sensor signal is out of range but wiring is intact, substitute a known-good sensor and recheck the code
After repairs, perform a full drive cycle and confirm the code does not reset, then verify charging system operation

Sensor circuit faults often mimic charger failure

A common misdiagnosis is replacing the entire auxiliary battery charger when the actual fault is a chafed signal wire or a corroded ground, so always perform voltage drop tests before condemning the module.
The code can set intermittently due to a loose connector that only loses contact during certain driving conditions, so a wiggle test of the harness while monitoring sensor data is essential.
On some vehicles, a weak or failing auxiliary battery itself can cause voltage sensor readings to fall outside the expected range, so load-test the battery before chasing circuit faults.
P0E86 does not always mean the charger has stopped working; it may simply indicate that the sensor's reported voltage is implausible, and the charger may still be functioning correctly.
Related codes for the auxiliary battery charger or voltage sensor circuit may be stored alongside P0E86, and addressing those first can sometimes resolve the root cause.

Can I keep driving with P0E86?

You can usually continue driving short distances to a repair shop, but avoid long trips or heavy electrical loads because a failing charger or sensor circuit can leave the auxiliary battery depleted and cause a no-start or reduced-power condition. If the vehicle enters limp mode or multiple warning lights appear, stop driving and seek professional diagnosis.

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.