P079B
Transmission Friction Element B Slip Detected
Same condition as element A slip, applied to friction element B (the second clutch or band).
- 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.
- Worn friction discs in element BCommon
Parts involved
- Clutch Pack B
- Transmission Fluid
P079B 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.