P060C: redundant calculations reveal processor-performance problems

P060C detects internal calculation faults in the cited GM examples. The sources describe checks intended to reveal RAM corruption, arithmetic-unit failures or ROM failures by comparing calculations, stored duplicates and calibrated bounds.

Gasoline and diesel examples differ

The 03A page explicitly labels its section gasoline only and includes equivalence-ratio torque compensation and accessory-torque comparisons. The 04B page labels its section diesel and includes torque-learning and other redundant-memory checks. These examples cannot establish the engine applicability of an unidentified vehicle.

The gasoline page includes a 52.90 Nm limit for certain differences. That is an internal comparison bound, not a measured crankshaft-torque tolerance or a recommended mechanical adjustment. The diesel example shows different quantities and limits.

Some displayed rows are inactive

Both sections explicitly say an individual test with a 2,048-millisecond diagnostic threshold is not applicable. They also say a sampled test is not applicable when its failure count exceeds its sample count. Consequently, copying every displayed row into a list of active P060C triggers would be incorrect.

For diagnosis, establish the controller, engine family and active calibration before interpreting an internal comparison. Preserve available subtest information rather than assuming every processor-performance code has the same cause. Verification should demonstrate the applicable redundant-calculation test passes after the prescribed repair or setup process; this summary supplies no universal reflash or controller-replacement remedy.

Source and applicability

Documented monitors in gm-2025-03a, gm-2025-04b, model year 2025. These are module/calibration examples; vehicle, engine and transmission applicability must be confirmed independently. GM 2025-03a, page 366. GM 2025-04b, page 584.