P0C37: Temperature sensor F has intermittent signal movement

P0C37 concerns intermittent or erratic output from hybrid/EV battery temperature sensor F. GM's 2018 HPC2/BSM implementation analyzes changes in that channel, so a plausible current temperature does not fully describe the fault.

Movement is measured without cancellation

The algorithm accumulates the absolute value of signal changes in a ten-sample window. An upward excursion and a downward excursion both add to the result. The listed threshold is above 10 for that integrated quantity, with four failed evaluations out of five at 100-millisecond intervals.

The monitor requires more than 10.2 V system voltage and absence of the defined battery-interface loss-of-communication faults. It is classified Type B, two trips. The source links erratic readings to a possible intermittent connection, without identifying a single mandatory repair.

A practical distinction

A fixed offset and an unstable signal are different observations. P0C37 specifically supports investigating the unstable pattern; the code alone does not prove the battery temperature is consistently too high. Preserve the recorded changes and compare their timing with the fault event.

Check that the scan data really represents sensor F and that communication was valid. The physical location of F must come from the vehicle-specific information. Repair verification should include a completed stability evaluation, not just a quiet display after resetting memory. Access to high-voltage battery sensors must follow the qualified service procedure.

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 903.