P0741: GR10 converter performance can be judged by K factor

P0741 commonly carries a torque-converter-clutch performance or stuck-off description. The GM row reviewed here is explicitly GR10-specific and describes a different-looking failure mechanism: a converter control valve hydraulically stuck on can allow converter drain-down, producing an excessive calculated K factor.

Understand the quantity being tested

The table defines K factor as engine speed divided by the square root of engine torque. Its fail limit is referenced to a supporting table rather than printed as one universal number. More than four failing counts within a 75-count sample, updated every 25 milliseconds, qualifies the listed Type A, one-trip fault.

A generic assumption that P0741 always means the clutch stayed disengaged would lose this calibration-specific distinction. Likewise, a torque estimate matters to this calculation; the continuation page excludes an inaccurate engine-torque estimate and several relevant speed-signal faults.

Why test conditions matter

The check requires a completed range shift, no intrusive shift, attained-gear slip below 75 rpm and converter speed ratio below 0.900. Engine torque must exceed 25 Nm. The listed transmission-fluid-temperature window is above −6.66°C and below 130°C, with additional voltage, speed and pedal conditions.

These conditions separate converter behavior from an ongoing shift or unreliable input data. Verification must establish that the K-factor monitor actually ran in its permitted operating window. The source does not justify replacing a converter or valve from the code alone. These details apply only to the documented GR10 strategy; identify the transmission and calibration before using them on a vehicle.

Source: GM monitor, PDF page 2063; GM monitor, PDF page 2064.