P0742 on Toyota
Torque Converter Clutch Circuit Stuck On
P0742 on Toyota vehicles indicates torque converter clutch circuit stuck on. Au7o has documented this code across 4 Toyota models — most commonly on 4Runner, Highlander, Tacoma. 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 Toyota range from $150 to $2,500, 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 Toyota by Model
Toyota 4Runner(1 issue)
- Transmission Shudder / Torque Converter Issues2010-2015
Some 4Runners experience a shudder during light acceleration, typically between 35-50 mph. The issue is often related to the torque converter lockup clutch or transmission fluid condition. Toyota released TSBs addressing fluid type and software updates.
Toyota Highlander(1 issue)
- 8-Speed Automatic Transmission Shudder and Hesitation2020-2024
The Direct Shift 8AT transmission in 4th-gen Highlanders exhibits shudder, hesitation on acceleration, and rough downshifts. The torque converter lockup clutch causes vibration at low speeds, particularly between 25-45 mph.
Toyota Tacoma(1 issue)
- 6-Speed Automatic Rough Shifting2016-2023
The 6-speed automatic transmission can exhibit rough or hesitant shifting, particularly between 1st and 2nd gear at low speeds. Some owners describe it as lurching or jerking. This is related to the transmission's adaptive learning and torque converter behavior.
Toyota Yaris(1 issue)
- 4-Speed Automatic Transmission Shudder and Harsh Shifts2007-2018
The U340E/U441E 4-speed automatic in the Yaris develops shudder during torque converter lockup and harsh shifts, particularly 1-2 and 2-3 shifts. Worn transmission fluid and torque converter clutch material are the primary causes.
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View P0742 across all makes →Frequently Asked Questions
What does P0742 mean on Toyota?▼
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 Toyota specifically, this code is documented across 4 models.
What causes P0742 on Toyota vehicles?▼
Common causes on Toyota: 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 Toyota?▼
Repair costs on Toyota range from $150 to $2,500, depending on the specific model and root cause.
Which Toyota models have P0742 documented?▼
Au7o has documented P0742 on 4 Toyota models: 4Runner, Highlander, Tacoma, Yaris.