P0BC3: Sensor E is compared with other battery temperatures

P0BC3 is the battery-temperature sensor E performance monitor in this GM table. It compares the sensor's reported temperature with the average temperature reported by other module groups. The problem is disagreement, not simply a temperature above a universal overheating limit.

Interpret the difference correctly

The failure boundary is an absolute deviation greater than 20°C. Either a higher or lower report can exceed that difference. The criterion must not be translated into “the battery is 20 degrees too hot,” because the comparison is between sensor reports and a reference average.

GM specifies 50 failing observations out of 67 at 100-millisecond intervals. The result describes repeated disagreement, rather than one isolated temperature sample captured during a changing operating condition.

Establish that the reference is usable

The temperature-rationality fault bundle must be false. That eligibility condition matters when other temperature-circuit or communication concerns affect the available measurements. Preserve the E reading, the comparison temperatures and relevant fault status for the diagnostic technician.

The table does not prove whether the difference is a real thermal condition or a sensor/reporting problem. Nor does the letter E identify a universal physical sensor location. A qualified high-voltage workshop must match the actual battery and its service information before inspecting components. The useful verification is a supported comparison under valid monitoring conditions, not simply clearing the code and watching the dashboard.

Source and applicability

15OBDG01 Hybrid Diagnostics, cited controller and monitor only. Historical calibration limits are not universal specifications; per-code vehicle, engine and hardware applicability must be verified.

GM source, physical page 586.