P079A
Transmission Friction Element A Slip Detected
Transmission
Generic OBD-II
Medium
What it means
P079A is set when the transmission control module detects that friction element A — a clutch or band inside the transmission — is slipping instead of holding firmly. The engine revs rise without matching road speed, and the slipping surfaces generate heat that can cause further damage. Low or degraded fluid and worn clutch components are the most common causes.
Medium
Can I keep driving? Drivable in the short term, but a slipping friction element generates heat and wear — keep trips short and repair promptly.
Common symptoms
What you'll notice
- Slipping or hesitation during acceleration
- Difficulty shifting, or harsh/delayed gear engagement
- Engine revs climb without a matching increase in speed
- Increased fuel consumption
- Check-engine light on
Common causes
Most likely first
- Low transmission fluid levelLikely
- Worn or damaged clutch plates / friction element ACommon
- Faulty shift or pressure control solenoid reducing apply pressureCommon
- Malfunctioning torque converterLess often
- Failed transmission control module (TCM)Less often
How to diagnose & fix
Work through it in order
- Check transmission fluid level and condition first; low or burnt fluid is a leading cause of slip — top up or service as needed.
- Read freeze-frame data to see the gear and load when the slip is detected.
- Test the apply solenoids and line pressure for that element; repair or replace faulty solenoids.
- Inspect the transmission for worn clutch/friction components; rebuild the affected element if worn.
- In severe cases, transmission overhaul or replacement may be required. Clear and road-test after repair.
FAQ
Quick answers
Is it safe to drive with P079A?+
Only briefly. A slipping friction element builds heat that can damage the transmission further, so minimize driving until it is repaired.
Can I just clear P079A?+
You can, but slip is usually mechanical or fluid-related, so it returns quickly and driving on it can worsen the damage.
Related codes
Often seen with P079A
Read & clear P079A yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX