P0C7C

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Generic P — Powertrain

Hybrid/EV Battery Temperature Sensor G Circuit

Brand: Generic

Type: P — Powertrain

Views: UK: 22 EN: 32 RU: 31

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Open or short in the sensor wiring harness (to ground or battery voltage)
Corroded, loose, bent or damaged connector terminals at the sensor or control module
Failed battery pack temperature sensor (thermistor)
High resistance from damaged wiring or water ingress
Faulty battery management/control module input or reference circuit
Recent battery pack service or connector disturbance not reassembled correctly

Hybrid/EV system warning light or battery system warning lamp illuminated
Reduced charging or discharge performance, limp-home or derate mode
Battery thermal management may not operate correctly (cooling/heating off or erratic)
Stored trouble code and freeze-frame data in battery management module
Possible loss of range or altered charge strategy

Read and record all stored DTCs and freeze-frame data from the battery management / hybrid control module
Visual inspection of sensor G connector, wiring harness, and grommets for damage, corrosion, or water intrusion
Backprobe signal, reference and ground pins with ignition on (per service manual) and observe voltages
Measure sensor resistance (pack isolated / HV system made safe) across sensor terminals and compare to expected thermistor curve
Wiggle test wiring and connectors while monitoring live data for intermittent changes
Inspect related junctions or multiplexed harnesses where several sensor leads route together

Reference supply commonly 5 V (check vehicle-specific values) — reference should be stable
Expected sensor voltage: typically ~0.5–4.5 V depending on pack temp and sensor type (consult factory spec)
Typical thermistor resistance example (vehicle-specific): ~10 kΩ at 25°C for many NTC types (confirm in service manual)
Open-circuit: very high/OL resistance or voltage at rail extreme; short-to-ground: ~0 V; short-to-Vref: ≈ Vref
Live data should change smoothly with temperature; sudden steps or frozen value indicate fault

Retrieve DTCs and freeze-frame; note conditions (battery SOC, pack temp, ignition state).
Follow safety procedures: disable high-voltage system and isolate battery before accessing pack connectors or sensor wiring. Only qualified personnel should work on HV systems.
Perform a visual inspection of the sensor G connector and wiring harness for damage, corrosion, moisture, or loose terminals.
With HV isolated and pack safe, disconnect the sensor connector and measure sensor resistance across sensor terminals; compare to manufacturer thermistor table over ambient temp.
Reconnect, reinstall HV as required for signal checks, backprobe the sensor connector with ignition on (or as specified) and measure reference voltage, signal voltage, and ground continuity at the harness connector near the control module.
If signal is out of range, trace wiring from sensor to module: check continuity, shorts to ground or battery voltage, and resistance at intervals along harness; repair any chafing or damaged sections.
If wiring and connectors are good but sensor resistance or voltage is out of spec, replace sensor G and retest.
If new sensor still shows fault and wiring is verified, test or replace the battery management/control module input circuit per factory diagnostics.
Clear DTCs and perform a functional test/short road or drive cycle to confirm the fault does not return and thermal management reacts normally.