P0C15: motor B phase V thermal diagnosis uses PIM Temp 0

P0C15 is motor B inverter phase V overtemperature in GM's parameter table. The source associates this diagnostic with PIM Temp 0. That assignment is specific to the documented controller and should not be inferred from a generic alphabetical sensor label.

Check the thermal monitor's eligibility

The PIM temperature must be in range, and the P0AF3 performance fault must not be active. These prerequisites separate a credible thermal event from a temperature value already judged electrically implausible or inconsistent.

The initial fault threshold is above 88°C, with a lower 85°C reset boundary. GM filters the condition through 500 qualifying counts among 650 at a 10.4 ms rate. The source lists one-trip reporting, which is separate from this within-monitor persistence requirement.

Use a temperature trend, not a replacement assumption

Capture the relevant temperature history and companion faults while preserving the original operating context. A cooled value observed later cannot establish whether the original sensing was valid or whether the cause of the thermal event has been corrected.

The document provides no universal cooling-system repair or mandatory inverter replacement. A trained hybrid technician must use vehicle-specific diagnostic information to determine the cause and verify recovery. High-voltage access requires the proper isolation procedure, and the temperature boundaries are not instructions to deliberately heat the inverter during an improvised test.

Source and applicability

GM 2010 10OBDG10 Hybrid Diagnostics, cited BPCM or hybrid-controller monitor only. Historical calibration values are not universal specifications; no per-code model, engine or hardware fitment has been established. GM PDF, physical page 302.