P079A: Clutch one slip is evaluated while the clutch is loaded and filled

P079A is the clutch-one slip monitor in this GM hybrid transmission table. The controller is checking whether C1 continues to slip after it has been commanded on under defined load and fill conditions. Slip during an unrelated operating state is not the same evidence.

Combine speed with the command state

The listed failure uses C1 slip above 200rpm for three seconds. At the same time, commanded pressure must be at least 1800kPa, estimated clutch torque at least 200Nm and clutch fill detected. These are command and estimate conditions; the pressure command is not itself a measured confirmation of hydraulic pressure.

The pass row uses slip below 50rpm, the same pressure-command threshold and a lower torque estimate requirement of 20Nm. It requires 0.125 seconds of passing behavior.

What the record can establish

Capture C1 slip together with pressure command, torque estimate and fill status. A high slip value without the required command or fill state does not reproduce the documented test. Conversely, the stored code alone does not distinguish inadequate applied pressure from a clutch or control problem.

The adjacent C2 monitor has a different failure duration, so its timing should not be borrowed for C1. The source gives no fluid-level procedure or internal repair decision. Those require vehicle-specific transmission information and a trained hybrid-transmission technician; this table is not an instruction to force clutch engagement for testing.

Source and applicability

GM 2010 10OBDG10 Hybrid Diagnostics, only the cited controller and monitor. These are historical calibration examples; individual vehicle, engine and hardware applicability is not established. GM PDF, page 197.