P0C7F

Code

Generic P — Powertrain

Hybrid/EV Battery Temperature Sensor G Circuit High

Brand: Generic

Type: P — Powertrain

Views: UK: 16 EN: 27 RU: 24

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Page language: EN

Causes

Open or intermittent connection at the G battery temp sensor
Short to battery voltage or sensor reference (pull-up to 12V/5V/3.3V)
Failed temperature sensor (thermistor or sensor module)
Corroded or damaged connector/pins or wiring harness
Water intrusion in connector or sensor assembly
HV battery pack connector or junction fault

Symptoms

HV battery temperature for sensor G reads implausibly high/low or shows out-of-range voltage in live data
HV battery warning lamp or MIL illuminated; reduced charging/traction or limp-home mode
Reduced regenerative braking or charging disabled
Stored related DTC(s) and freeze frame data showing abnormal temps or voltages
Possible inability to perform battery thermal management (fan/heater) properly

What to check

Retrieve all stored/current DTCs and freeze-frame data; note battery pack state-of-charge and temperatures
Review freeze-frame live data for sensor G voltage and reported temperature
Visually inspect sensor G connector, wiring harness, junctions and any intermediate connectors for corrosion, damage, water intrusion or pin push-out
Confirm safety: follow manufacturer HV isolation/lockout procedure before touching any HV components
Backprobe signal and reference pins at the sensor with vehicle in the correct key state (usually IGN ON, engine off) and record voltage
Compare measured voltage to expected reference (see signal_params). Check for presence of reference voltage and ground at the connector

Signal parameters

Typical sensor type: thermistor (NTC) with a signal voltage referenced to vehicle reference (commonly 3.3V or 5V supply) — manufacturer-specific
Circuit high condition: sensor signal voltage near the reference/supply rail (e.g., ≈3.0–3.3V on 3.3V systems or ≈4.5–5.0V on 5V systems) or above expected maximum for normal temp range
Normal operating sensor voltage: varies with temperature and sensor type; expected mid-range voltages typically between ~0.2–3.0V depending on system and pack temperature
Resistance behavior for common NTC sensors: resistance falls as temperature rises (verify with manufacturer data — many EV pack sensors are ~10 kΩ at 25°C, but this is vehicle-specific)

Diagnostic algorithm

Read and record P0C7F and any related codes; clear codes only after documenting freeze-frame. Note pack SOC and ambient temperature.
Verify HV safety procedures and isolate high-voltage system before accessing battery connectors or sensor hardware.
Visually inspect sensor G harness and connectors for corrosion, damage, water, or crushed wires. Repair as needed.
With ignition ON (engine off) and using proper HV precautions for nearby components, backprobe the sensor connector: verify presence of reference voltage and good ground at the ECU side. If reference is missing, trace back to ECU/fuse/junction.
Measure sensor signal voltage at the connector. If signal is at or near supply rail, suspect open sensor or short to supply. If signal is floating or 0V, suspect short to ground or open reference.
Remove sensor if accessible and measure sensor resistance vs ambient temperature. Compare to manufacturer table or expected thermistor behavior (NTC decreases with heat). If open or out-of-spec, replace sensor.
If wiring is suspect, perform continuity checks from sensor pin to ECU pin and check for shorts to battery + and to ground. Repair damaged wiring or connector pins.
After repairs, reconnect, clear codes, and monitor live data while performing a controlled battery temperature exercise or test drive to confirm normal behavior and no recurrence.
If wiring and sensor check good but fault persists, consider suspect battery management ECU/module and follow manufacturer diagnosis for ECU replacement or repair.

Likely causes

Connector corrosion or broken pin at the sensor or junction
Open circuit in sensor return/ground conductor or harness damage from routing/chafing
Sensor element failed open (thermistor open or out-of-spec)
Shorted sensor signal to battery positive or reference voltage
Poor crimp or intermittent connector contact

Fault status

⚠️ Status

P0C7F — Hybrid/EV Battery Temperature Sensor G Circuit High: Sensor signal voltage above expected range. System may store DTC, set fault indicator, and restrict battery charging/drive functions until condition cleared.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.5-3.0 hours