Powertrain
generic / SAE
P0729
Gear 6 Incorrect Ratio
When gear 6 is engaged, the measured ratio between the input- and output-shaft speed sensors does not match the expected ratio for that gear. This means the transmission is slipping in gear 6 rather than transmitting power solidly. Causes: worn clutch packs or bands, low fluid level or pressure, a stuck shift solenoid, or a valve-body fault affecting gear 6.
SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number7 / 29
Possible causes
- Shift solenoid stuck high
- Clutch pack worn or slipping medium
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
Inspection / repair
- Difficulty: hard
- DIY: shop recommended
- Estimated cost: 200–3000 €
- Estimated time: 1.5–12 h
- Component: automatic transmission
- Component: shift solenoid
- MIL / check engine light
- limp mode possible
Sources
References
sae:J2012