P0C72

Code

Generic P — Powertrain

Hybrid/EV Battery Temperature Sensor E/F Correlation

Brand: Generic

Type: P — Powertrain

Views: UK: 27 EN: 36 RU: 41

AI status

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Page language: EN

Causes

One or both battery temperature sensors (E or F) producing incorrect resistance/voltage
Open, short, or high-resistance wiring between sensors and battery management ECU
Poor connector contact, corrosion, damaged pins or water ingress at sensor connectors
Incorrect sensor installation or shifted sensor location (mechanical)
Intermittent wiring fault that changes under vibration/temperature
Battery management ECU internal fault or software/calibration issue

Symptoms

DTC P0C72 stored; MIL may or may not be illuminated depending on manufacturer strategy
Incorrect battery state-of-charge/thermal management behavior (reduced charging/heating/cooling) reported
Reduced EV/hybrid performance or limited charging/heating strategies from battery management
Intermittent thermal system faults or warning messages related to battery temperature
Possible warning lights or reduced drivability modes if pack thermal protection is triggered

What to check

Read and record freeze frame data and all related battery/thermal codes
Visually inspect battery-pack area around sensors E and F for damage or contamination
Inspect connectors and pins for corrosion, bent pins, or water ingress
Backprobe sensor signal and reference wires with ignition ON and engine/vehicle in required state
Compare sensor voltages/resistances between sensor E and F at ambient temperature
Check wiring continuity and for short to battery positive or ground

Signal parameters

Reference supply typically 5 V (verify vehicle-specific value) — should be present at sensor connector
Sensor output voltage typically within 0.1–4.9 V range depending on temperature; zero or rail voltage indicates open/short
Thermistor resistance changes with temperature (NTC: resistance falls as temperature rises) — measure resistance at known temps
Expected difference between adjacent pack sensors is small (manufacturer threshold); P0C72 triggers when difference exceeds threshold
Check CAN/battery management data stream for reported temperatures and sensor correlation values

Diagnostic algorithm

Retrieve all related codes and freeze frame information from the battery management system and body/ECU modules.
Verify the code is current/repeatable. Clear codes and perform drive/soak cycle or required test to see if code returns.
Visually inspect sensor E and F mounting, harness routing, and connectors for damage, corrosion, pin deformation or water intrusion.
With ignition ON (or as specified), backprobe each sensor connector and measure reference voltage, signal voltage, and ground continuity. Compare readings between E and F.
Measure sensor resistances (with connector disconnected) at ambient temperature and, if safe, apply heat/cold to confirm resistance changes. Compare both sensors for similar characteristics.
If a sensor shows open/short or out-of-range values, replace that sensor and retest. If both sensors measure correctly but still mis-correlate, inspect harness for intermittent faults — wiggle test under monitoring.
Check for short or cross-connection between adjacent sensor circuits and for shared grounds that could introduce error.
If wiring and sensors test OK, inspect battery management ECU connectors and verify proper grounds and reference supply at the module. Consider ECU module fault if wiring and sensors are confirmed good.
After repairs, clear codes and perform required verification procedure (soak/drive cycle or manufacturer-specific validation) to confirm fault does not return.
If diagnosis remains inconclusive, consult manufacturer technical information or apply updates/recalls/TSBs and consider module bench testing by qualified technician.

Likely causes

Loose, corroded or pinched connector on one of the temperature sensors
Broken or shorted wire in the sensor harness between the sensor and battery ECU
Failed temperature sensor (thermistor) on sensor E or F
Sensor mounted incorrectly or has become detached from pack surface
Ground or reference voltage (5 V) fault affecting one sensor circuit

Fault status

⚠️ Status

Battery temperature sensor E and F readings do not correlate within allowed limits. Possible sensor, wiring, connector, or battery management module issue affecting temperature measurements.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.5 - 3.0 hours