P0798: SLC2 current feedback differs persistently from demand

GM's group 04 P0798 entry belongs to the SLC2 solenoid channel. It compares target current with measured feedback and accumulates the difference. This electrical-current evidence is distinct from directly measuring clutch pressure or judging shift feel.

The direction and persistence of error matter

The error is added every ten milliseconds. The accumulated result is reset if the detection window closes, the difference returns within the specified near-zero band or the error changes sign. A signal that continually returns toward its target therefore differs from a sustained deviation in one direction.

The controller requires suitable ignition voltage, an enabled diagnostic state and no emergency mode. Related low- and high-circuit codes must be absent. If those prerequisites are not met, lack of a new P0798 is not evidence that current tracking has passed.

Identify the correct solenoid channel

The generic code uses pressure-control solenoid C, while this document labels the associated channel SLC2. Confirm the exact transmission's mapping before any electrical test. The letters do not establish a universal physical location.

Preserve requested current, feedback current and related faults where the diagnostic equipment makes them available. Use the applicable service procedure to distinguish electrical causes. Verification requires credible tracking and a completed monitor; an erased code or temporary improvement in shifting does not demonstrate that the original current error is corrected.

Source and applicability

2009 General Motors diagnostic parameter file 09OBDG04 TRANS Diagnostics.pdf. Section-specific modules and calibrations; no per-code model or engine applicability established. This explanation describes the documented monitor, not a universal repair procedure.

GM diagnostic parameters, PDF page 5.