P0742 on Mazda: How to Diagnose & Fix
Torque Converter Clutch Circuit Stuck On
1 Mazda model · 1 documented issue · $150-$1,800 repair
P0742 on Mazda by model: symptoms, diagnosis and fix
The 6-speed automatic transmission in the CX-3 develops a shudder or vibration during light-throttle acceleration at low to moderate speeds (20-45 mph). The torque converter lockup clutch is the typical culprit, with worn friction material causing slip-stick behavior. A transmission fluid change can temporarily resolve the issue, but severe cases require torque converter replacement.
Common Symptoms
- Vibration or shudder during light acceleration at 20-45 mph
- Feels like driving over rumble strips
- Shudder disappears under hard acceleration or deceleration
- Transmission temperature warning in extreme cases
How to Fix
Perform a complete transmission fluid drain and fill with Mazda ATF FW (not a flush). If shudder persists after fluid change, torque converter replacement is required. TCM reprogramming may also improve shift quality.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- BLAU/Ravenol CX-3 ATF-FZ drain-and-fill kit F2A1421-COEMBLAU F2A1421-C / Mazda ATF-FZ 0000-FZ-113E-01 specification
Measured drain-and-fill service for 2016-2021 CX-3 six-speed automatic Fitment/availability: Indexed direct page identifies five liters of ATF meeting Mazda 0000-FZ-113E-01 plus filter/service hardware, 2016-2021 CX-3 six-speed fitment, …
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Owner tips & cautions
- TipTry drain-and-fill (not flush) first - may resolve shudder for $150-200
- TipChange transmission fluid every 30,000 miles as preventive maintenance
- TipIf fluid change does not resolve it, torque converter replacement is the permanent fix - MazdaCX3Forum.com
Sources for this issue (1)
P0742 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0742 mean on a Mazda?
P0742 stands for "Torque Converter Clutch Circuit Stuck On." P0742 means the torque converter clutch (TCC) circuit is stuck on, meaning the lockup clutch that mechanically links the engine to the transmission stays engaged when it should release. The computer commands the clutch on and off, and when it detects the converter clutch remaining applied, it sets this code. The classic symptom is the engine stalling when coming to a stop, similar to driving a manual without pushing the clutch in, along with possible harsh shifts or poor fuel economy. It points to a hydraulic or solenoid problem inside the transmission rather than the engine. On Mazda it is documented across 1 model: CX-3.
What are the most common causes of P0742?
The most common causes of P0742 are: Stuck or failed torque converter clutch solenoid, Stuck valve in the valve body (TCC apply valve), Contaminated or degraded transmission fluid, Internal transmission hydraulic leak holding the clutch on, Wiring or connector fault to the TCC solenoid, Faulty torque converter, Dirty or clogged transmission filter. The specific cause varies by vehicle.
How much does it cost to fix P0742 on a Mazda?
Published repair estimates on Mazda range from $150 to $1,800 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0742 on a different make?
View P0742 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.