P0742 on Mazda
Torque Converter Clutch Circuit Stuck On
P0742 on Mazda vehicles indicates torque converter clutch circuit stuck on. Au7o has documented this code across 3 Mazda models — most commonly on CX-3, CX-50, Mazda6. 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. Typical repair costs on Mazda range from $150 to $2,000, depending on the specific model and root cause.
Common Causes of P0742
- •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
P0742 on Mazda by Model
Mazda CX-3(1 issue)
- Automatic Transmission Shudder2016-2021
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.
Mazda CX-50(1 issue)
- Transmission Hesitation on Acceleration2023-2025
The 6-speed automatic transmission in the CX-50 exhibits hesitation and delayed shifts when accelerating from a stop or during passing maneuvers. The torque converter lockup strategy and shift programming prioritize fuel economy over responsiveness, causing a noticeable lag. Some owners report improvement after TCM recalibration.
Mazda Mazda6(1 issue)
- Clutch Judder on SkyActiv Manual Transmission2014-2021
Manual transmission Mazda6 SkyActiv models experience clutch judder similar to the Mazda3 issue. The dual-mass flywheel and clutch disc friction material cause shuddering during engagement, especially from a stop. Mazda acknowledged the issue via technical service bulletin.
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View P0742 across all makes →Frequently Asked Questions
What does P0742 mean on 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 specifically, this code is documented across 3 models.
What causes P0742 on Mazda vehicles?▼
Common causes on Mazda: 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. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0742 on a Mazda?▼
Repair costs on Mazda range from $150 to $2,000, depending on the specific model and root cause.
Which Mazda models have P0742 documented?▼
Au7o has documented P0742 on 3 Mazda models: CX-3, CX-50, Mazda6.