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P079A Transmission Friction Element "A" Slip Detected

The OBD2 code P079A indicates that the transmission control module has detected a slip condition in the friction element "A" of the transmission, which may suggest issues with the transmission's ability to engage or...

Definition

The OBD2 code P079A indicates that the transmission control module has detected a slip condition in the friction element "A" of the transmission, which may suggest issues with the transmission's ability to engage or maintain proper pressure in that element

Common causes

  • Low transmission fluid level
  • Contaminated transmission fluid
  • Faulty transmission control module (TCM)
  • Worn or damaged transmission components
  • Faulty solenoid or actuator
  • Electrical issues (wiring or connectors)
  • Malfunctioning torque converter
  • Incorrect transmission fluid type
  • Software issues or updates needed in the TCM
  • Mechanical binding or sticking in the transmission system

Common misdiagnoses

  • Transmission fluid issues (low level, contamination)
  • Faulty transmission control module (TCM)
  • Worn or damaged transmission components
  • Incorrectly calibrated or malfunctioning sensors
  • Engine performance issues (misfires, fuel delivery problems)
  • Electrical issues (wiring, connectors)
  • Torque converter problems
  • Software or firmware issues in the transmission system

Troubleshooting steps

  1. 1. Check for Additional Codes

    Use an OBD-II scanner to check for any other related trouble codes. Codes related to the transmission or engine can provide more context for the issue

  2. 2. Inspect Transmission Fluid

    Fluid Level: Check the transmission fluid level. Low fluid can cause slipping

  3. 3. Fluid Condition

    Inspect the fluid for contamination, burning smell, or dark color. If the fluid is dirty or burnt, it may need to be changed

  4. 4. Fluid Type

    Ensure the correct type of transmission fluid is being used

  5. 5. Examine the Transmission Filter

    If the transmission has a filter, check it for clogs or restrictions. A clogged filter can restrict fluid flow and cause slipping

  6. 6. Check for Leaks

    Inspect the transmission and surrounding areas for any signs of fluid leaks. Leaks can lead to low fluid levels and slipping

  7. 7. Inspect Electrical Connections

    Check the wiring and connectors related to the transmission, including the TCM and any solenoids. Look for corrosion, damage, or loose connections

  8. 8. Test Transmission Solenoids

    The solenoids control the flow of transmission fluid. If they are malfunctioning, they can cause slipping. Use a multimeter to test the solenoids for proper resistance and operation

  9. 9. Perform a Transmission Fluid Flush

    If the fluid is dirty or burnt, consider performing a transmission fluid flush to remove contaminants and replenish the fluid

  10. 10. Check for Mechanical Issues

    Inspect the transmission for any mechanical issues, such as worn clutches, bands, or other internal components. This may require disassembly and inspection by a professional

  11. 11. Update or Reprogram TCM

    Sometimes, a software update or reprogramming of the TCM can resolve issues related to shifting and slipping. Check with the manufacturer for any available updates

  12. 12. Consult a Professional

    If the issue persists after performing the above steps, it may be necessary to consult a professional mechanic or transmission specialist for further diagnosis and repair.1

  13. 13. Clear Codes and Test Drive

    After performing any repairs or maintenance, clear the codes and take the vehicle for a test drive to see if the issue reoccurs.Conclusion Addressing a P079A code requires a systematic approach to identify the root cause of the slipping condition. Always refer to the vehicle's service manual for specific procedures and specifications related to the transmission system