P0C08: motor B circuit-open detection uses a position-dependent current test

P0C08 is the motor B U-V-W circuit/open row in GM's MCPB section. It checks for a missing phase-current response near the relevant rotor phase axis. The source's short strategy sentence says motor A, despite the motor B heading and section; that inconsistency is retained for review.

Reconstruct the supported current sequence

The row requires both non-peak phase sensors above the stated 9 A magnitude, followed by phase-axis current below that magnitude. Rotor position must be in the printed phase-axis window. Inverter RUN state, voltage above 35 V and a minimum peak phase-current condition are also required.

These dependencies distinguish the monitor from a simple low sensor reading with output disabled. Current and rotor-position evidence must be assessed together rather than inferred from one channel sampled later.

Do not invent the missing detail

The timing cell lists a preliminary task-loop interval and a further count-based interval but leaves the final total incomplete. This article does not reconstruct a universal total duration or silently correct the motor-name sentence. Confirm the applicable calibration and signal mapping before using the monitor for a repair decision.

The code does not physically locate an open connection or mandate motor replacement. A qualified hybrid technician must follow the actual vehicle's diagnostic and high-voltage safety procedures. The monitor logic is not an instruction to manually energize or rotate the motor for testing.

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 296.