P0961: CVT secondary pressure and ratio error confirm a performance fault

P0961 is pressure-control solenoid A performance. The cited TCM implementation concerns the CVT secondary-pulley solenoid and evaluates pressure response together with variator ratio control.

The monitor uses two comparisons

Measured pulley pressure is compared with its command. When pressure error is sufficient, the controller checks average speed-ratio error. The displayed failure logic requires ratio error above 0.2000 and pressure error above 500 kPa in steady state or above 1,500 kPa outside steady state.

Those paired criteria matter: one pressure snapshot does not reproduce the full monitor, and a normal-looking ratio at a different time does not refute an earlier combined failure. Preserve synchronized pressure and ratio information when available.

Operating-state timing is not one fixed timeout

The source gives separate steady-state and nonsteady-state ratio-error time conditions, along with pending and additional delay entries. It does not justify collapsing the entire test into a single universal duration. The corresponding enable calibrations and valid engine-speed information also matter.

This is a system-performance diagnostic, not the open/low/high electrical classification of the neighboring solenoid-A codes. The published strategy uses ratio behavior to strengthen the actuator-performance conclusion, but the summary still does not supply a complete repair tree or mandatory replacement. Verification should demonstrate satisfactory commanded secondary pressure and ratio response through the applicable enabled CVT monitor. These pulley-specific facts should not be applied to another transmission solely because its generic code title matches.

Source and applicability

Documented monitors in gm-2025-03a, model year 2025. These are module/calibration examples; vehicle, engine and transmission applicability must be confirmed independently. GM 2025-03a, page 1140.