Powertrain
generic / SAE
P079A
Transmission Friction Element A Slip Detected
Friction element A (the first clutch or band in the gear matrix) shows measurable slip while it should be fully engaged. Detected by comparing input/output speed sensors against the commanded gear ratio. Slip means the element cannot transmit full torque — risk of glazing the friction surfaces.
SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number7 / 9A
Possible causes
- Worn friction discs in element A high
- Low hydraulic pressure to element A medium
- Old ATF lacking friction modifier 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: 600–4000 €
- Estimated time: 3–12 h
- Component: clutch pack a
- Component: transmission fluid
- MIL / check engine light
Sources
References
sae:J2012