P07D8
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.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: hard
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
Common causes
Ordered by how often each turns out to be the cause.
- Solenoid stuck closedCommon
- Slipping clutch in 8th gear elementPossible
Parts involved
- Shift Solenoid
- Clutch Pack
P07D8 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.