Unable To Engage Gear 8
The TCM commands a shift to 8th gear but the gear-ratio measurement does not confirm engagement — friction element does not lock up, slipping clutch, or shift solenoid does not respond. Falls back to the previously engaged gear.
Affected components
- Shift solenoid
- Clutch pack
Common causes
- High likelihood: Solenoid stuck closed
- Medium likelihood: Slipping clutch in 8th gear element
Possible symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
Diagnostic notes
- The malfunction indicator lamp may illuminate
Related codes
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.