Mazda – Automatic Transmission Failures (Valve Body Issues, Slipping)

Mazda3 and Mazda6 models equipped with FN4A‑EL, FS5A‑EL, and FW6A‑EL automatic transmissions have documented reliability issues involving valve body wear, slipping, harsh shifting, delayed engagement, and premature internal failure. These problems are most common in 2004–2013 Mazda3 and 2003–2013 Mazda6 models, with some later FW6A‑EL units also showing valve body degradation.

Year(s) Make Model Should Purchase? Notes
2004 2005 2006 2007 2008 2009 Mazda Mazda3 Caution Transmission: FN4A‑EL (4‑speed automatic)
Issues: valve body wear, slipping between 2–3, delayed engagement, harsh downshifts
Notes: early FN4A‑EL units prone to solenoid failure and pressure loss; rebuild or valve body replacement common
2010 2011 2012 2013 Mazda Mazda3 Caution Transmission: FW6A‑EL (6‑speed automatic)
Issues: valve body degradation, flare on upshifts, slipping under load
Notes: improved over FN4A‑EL but still susceptible to valve body pressure loss; TCM updates sometimes required
2003 2004 2005 2006 2007 2008 Mazda Mazda6 Caution Transmission: FS5A‑EL (5‑speed automatic)
Issues: slipping, harsh shifts, valve body failure, delayed engagement
Notes: shared with Ford CD3 platform; known for solenoid and valve body wear leading to early rebuilds
2009 2010 2011 2012 2013 Mazda Mazda6 Caution Transmission: FW6A‑EL (6‑speed automatic)
Issues: slipping under acceleration, flare shifts, valve body pressure loss
Notes: later FW6A‑EL units improved but still show valve body wear at higher mileage

Summary of Mazda Automatic Transmission Defect Patterns

Legal context

While Mazda automatic transmission failures did not result in a major class action like the Denso fuel pump or SKYACTIV‑G 2.5T coolant defect, numerous TSBs were issued for valve body problems, slipping, and harsh shifting. Many owners received goodwill repairs or partial reimbursement for transmission rebuilds.

References