P0C58: resolver circuit A high needs the motor B source-label caveat

P0C58 is generically motor B position-sensor circuit A high. In the GM document it appears under the motor B resolver-circuit section, but the individual row heading says motor A. That inconsistency matters before assigning the code to physical hardware and is retained for review.

The supported electrical criterion

The row's measured quantity is resolver S13 circuit reference voltage. Its high threshold is above 3.0 V with the wakeup signal on. GM lists twenty qualifying counts among thirty at a 10.4 ms rate and one-trip reporting.

Those facts describe a reference-voltage range check. They do not establish excessive rotor angle, motor overspeed or a completed resolver-learning failure. Preserve related code states rather than collapse those different diagnostic categories.

Confirm the channel before physical testing

The motor B section and generic code identity support the intended context, while the conflicting row heading prevents treating this summary as a definitive wiring map. Use the exact vehicle and controller service information to confirm the motor and S13 circuit assignment.

The table does not prescribe replacement or provide a safe connector test. A trained hybrid technician must establish proper high-voltage isolation for physical work and verify a credible reference signal during eligible operation. The published threshold should not be reproduced by voltage injection, and deleting the fault record does not resolve the source-mapping uncertainty.

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 304.