P0C95

Code

Generic P — Powertrain

Hybrid/EV Battery Temperature Sensor K Circuit High

Brand: Generic

Type: P — Powertrain

Views: UK: 29 EN: 34 RU: 29

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Page language: EN

Causes

Open or high-resistance wiring between the sensor and the battery control module (BCM/ECM)
Disconnected, corroded, damaged or contaminated connector at the battery temperature sensor
Failed/shorted temperature sensor (thermistor open or out-of-spec)
Water intrusion or insulation breakdown in wiring harness
Poor or missing ground or reference voltage to the sensor circuit
Faulty battery management module / control module input circuit

Symptoms

Hybrid/EV system reduced power, limp or limited operation
HV battery/heater/AC charging inhibited or reduced charging rate
Battery temperature gauge or display shows incorrect or extreme temperature
Check Hybrid System / Service Electric Vehicle warning illuminated
Possible inability to enter EV mode or reduced regenerative braking

What to check

Observe freeze-frame / live data for sensor voltage/temperature from scan tool
Visually inspect sensor connector and harness for damage, corrosion, water, chafing
Check connector mating – pins straight and fully seated
Measure sensor circuit voltage with a DMM at the sensor connector (with ignition per service manual)
Measure resistance of the temperature sensor (pack isolated / per procedure) and compare to expected thermistor curve
Perform continuity check from sensor connector to the battery control module connector

Signal parameters

Typical signal voltage range: 0–5 V (varies by manufacturer; many systems use an ADC input with pull-up/pull-down)
A temperature sensor is commonly an NTC thermistor: resistance decreases as temperature rises
Open-circuit usually results in a high circuit voltage (pulled to reference supply), or an out-of-range temperature reading
Expected resistance at ~25°C typically falls within a manufacturer-specific range (consult service data)

Diagnostic algorithm

Safety first: follow manufacturer high-voltage safety procedures. Disable HV system and wear appropriate PPE before accessing the battery pack or wiring.
Retrieve freeze-frame and live data: record sensor voltage/temperature and related pack voltages.
Perform visual inspection of the sensor lead, connector and harness for damage, corrosion, or moisture ingress. Repair any obvious damage.
With ignition on (per service manual) measure voltage at the sensor signal pin and reference/ground. Note if voltage is at or near supply voltage (indicates open/high).
Disconnect sensor and measure resistance across sensor terminals (pack isolated if required). Compare measured resistance to manufacturer thermistor chart across temperature. An open or out-of-spec reading indicates a faulty sensor.
Check continuity between the sensor connector and BCM/ECM connector. Repair any opens or high-resistance joints; replace damaged harness sections.
If wiring and sensor check good, inspect module connector pins for damage and measure module input circuit for proper pull-up/pull-down behavior (refer to service manual).
If direct short to supply or ground is found, repair wiring and recheck. If module input is suspected after harness/sensor verified, consult manufacturer for module testing or replacement.
Clear DTCs and perform drive/operational test. Re-scan for recurrence and monitor live sensor readings under normal temperature conditions.

Likely causes

Connector pin pulled out or corroded at the sensor or module
Broken conductor inside harness (intermittent or open)
Sensor element (thermistor) open-circuit or aged out of spec
High-resistance splice or crimp joint causing circuit voltage to float high
Module internal input failure (less common)

Fault status

⚠️ Status

Hybrid/EV Battery Temperature Sensor K Circuit High - sensor circuit voltage higher than expected; possible open or high-resistance circuit, failed sensor, connector or wiring fault. Requires HV-safe diagnosis.

🔴 Repair difficulty: Hard

⏱️ Diagnostic time: 1-4 hours