P07D9
Gear 8 Incorrect Ratio
While in 8th gear, the measured input/output ratio does not match the calibrated value — slipping clutch, wrong gear actually engaged, or speed sensor data wrong.
- 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.
- Slipping clutch in 8th gear elementCommon
Parts involved
- Clutch Pack
- Speed Sensors
P07D9 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.