P07AB: Clutch 5 does not develop the expected release slip

P07AB generically means transmission friction element E stuck on. The 2018 GM HPC1 “CT6 Unique” table calls it clutch 5 stuck on and evaluates slip during an offgoing or released state. It is the opposite operating question from a locked clutch slipping excessively.

Missing slip can be fault evidence

One branch monitors the offgoing state with valid motor-speed information. Another compares actual clutch 5 slip with a desired slip profile when clutch status is released and no shutdown is commanded. The table requires a failure for two seconds in a 2.68-second window and lists Type A, one-trip reporting.

The relevant thresholds in the released-state branch are named calibration functions in supporting tables, not a universal rpm value. They should not be replaced with a guessed number from another transmission.

Preserve the transition

A steady snapshot taken after the shift can miss the offgoing profile that produced the fault. Record the requested clutch state, actual slip, expected/profiled slip information and motor-speed validity where the diagnostic system provides them.

This result indicates failure to achieve the expected release behavior; it does not identify a mechanical sticking point, hydraulic cause or controller failure from the code alone. A qualified transmission technician should use the correct application procedure. Repair verification must address the release transition safely under the prescribed conditions, rather than relying only on a cleared historical code or an ordinary parked observation.

Source and applicability

This explanation follows the documented GM monitor, not a verified application to every vehicle with this code. Confirm the vehicle, reporting module and calibration in current service information. GM diagnostic table, physical page 1820.