P0C93: Sensor K fails a comparison with other battery temperatures

P0C93 concerns hybrid/EV battery temperature sensor K range/performance. GM's 2018 controller checks whether K's temperature is consistent with an average formed from other battery sensors. It is a relative plausibility check, not simply an electrical high- or low-limit code.

Direction is not specified by the DTC

A difference above 25 °C in either direction meets the listed threshold because the calculation uses absolute difference. The monitor requires 50 failures among 67 samples, taken every 25 milliseconds, and is classified Type B, two trips.

The table excludes active faults from the temperature circuit-low, circuit-high, erratic and battery-interface communication groups. That makes the health of the comparison inputs relevant: if they are invalid, the performance test may not run.

What to compare

Keep sensor K's value with the other temperature readings at the time of failure. The DTC cannot say whether K is too warm or too cold without those values, and it does not independently establish which reading is correct. A stable signal can still be implausible relative to its peers.

Use the vehicle-specific temperature-sensor mapping and diagnostic sequence. After correction, confirm that the comparison executes without inhibiting faults and that the readings are credible. A missing repeat code during an inhibited test is not verification. Qualified high-voltage service is required for internal pack access; this table does not locate sensor K physically.

Source and applicability

This explanation follows the documented GM monitor, not a verified application to every vehicle with this code. Confirm the vehicle, reporting module and calibration in current service information. GM diagnostic table, physical page 921.