P0C8A: Sensor I low circuit and a hot converted report

P0C8A is the low-circuit diagnosis for battery-temperature sensor I in this GM controller. Its explicit threshold is ADC below 680 with reported temperature above 87.5°C. The code therefore cannot be explained simply as a low physical battery temperature.

Separate the electrical finding from real heat

The displayed temperature is a conversion of the sensor signal. A high converted value with a circuit fault is not independent confirmation that the battery is actually that hot. The applicable circuit procedure must establish whether the measurement is trustworthy.

The low-signal condition must occupy 1.4 seconds of a two-second window, sampled every 200 milliseconds. Recovery requires at most 87.5°C with ADC at least 680 for two seconds. Both magnitude and persistence matter when comparing the event with a later normal-looking reading.

Preserve the operating context

Enabled communication, absence of the listed sensing-module communication and internal-performance faults, and an inactive secondary protection self-test are prerequisites. A retest without those conditions cannot provide the same diagnostic assessment.

The source strategy sentence says temperature falls below a limit, which conflicts with its explicit converted-temperature direction. That wording remains a review flag; the article does not invent a replacement threshold. The I channel's physical location must be determined from the exact battery documentation. Any high-voltage battery access requires qualified personnel and the correct vehicle service precautions.

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 639.