P0C43: Battery inlet-temperature plausibility depends on thermal mode

P0C43 is the battery-coolant inlet-temperature plausibility check in this GM controller. It compares the inlet report with both outlet coolant temperature and average battery-cell temperature. The code does not simply mean that one sensor exceeded an absolute temperature limit.

Thermal mode changes the comparison

For the clearly labelled active-heating branch, the table requires both absolute differences to reach at least 30°C. In the passive-cooling branch, the displayed boundary is 55°C. Applying one number without identifying the controller's thermal mode would misread the monitor.

Pump speed must be at least 20 percent for more than one minute. Following a thermal-mode change, at least 70 seconds must have elapsed. These conditions show why a comparison made immediately after a mode transition or before established circulation may not reproduce the test.

Retain the relevant faults and timing

System voltage must exceed 10.2 volts, and the listed temperature, pump and communication faults must be absent. Qualification uses 32 failures among 40 samples at 250-millisecond intervals. Preserve both reference temperatures and the enabled state when judging the event.

The original table contains an incompletely labelled middle branch; this article does not guess its thermal mode. The supported branches still establish that context and circulation matter. Sensor replacement or physical high-voltage cooling work requires the correct vehicle service procedure and qualified diagnosis, rather than the code alone.

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 560 · GM source, physical page 561.