P0742 on Toyota: How to Diagnose & Fix
Torque Converter Clutch Circuit Stuck On
4 Toyota models · 4 documented issues · $150-$2,500 repair
P0742 on Toyota by model: symptoms, diagnosis and fix
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.
Common Symptoms
- Rough 1-2 shift at low speeds
- Lurching when accelerating gently
- Hesitation from stop
- Clunk when shifting
- Jerky driving in traffic
How to Fix
Ensure transmission software is updated. Transmission may need adaptive learning reset. Regular transmission fluid changes help. Toyota has issued TSBs with software updates for some model years.
Owner tips & cautions
- TipRegular transmission fluid changes help.
- TipGet a proper diagnosis before replacing parts - similar symptoms can have different causes
- TipSearch Toyota Tacoma forums and owner groups for real-world experiences and DIY guides
- TipGet multiple quotes from independent mechanics - dealer prices can be 2-3x higher for the same repair
Sources for this issue (1)
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.
Common Symptoms
- Shudder at 25-45 mph under light throttle
- Hesitation on acceleration from stop
- Rough downshifts when slowing
- Vibration felt through seat and steering wheel
How to Fix
Visit dealer for TCM software update (TSB 0011-21). Transmission fluid drain and refill with Toyota WS ATF may help. Some owners report improvement after the transmission 'learns' driving habits over 5,000+ miles. Persistent cases may need torque converter replacement.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Toyota 00289-ATFWS genuine World Standard automatic transmission fluid, 1 quart
correct fluid only when level correction or a repair-manual drain-and-refill is indicated after diagnosis Fitment/availability: VIN-confirmed 2020-2024 Highlander automatic transaxle that specifies Toyota WS; quantity follows the measure…
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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.
Common Symptoms
- Shudder at 25-40 mph during light throttle
- Harsh 1-2 and 2-3 gear shifts
- Transmission slipping sensation
- Delayed engagement from Park to Drive
How to Fix
Perform triple drain-and-fill with Toyota WS ATF (or Toyota Type T-IV for older models). If shudder persists, torque converter replacement. Regular ATF changes every 30,000 miles prevent the issue. The 4-speed automatic is otherwise quite reliable when maintained.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Toyota 00289-ATFWS genuine World Standard automatic-transmission fluid, 1 quart
measured refill only after diagnosis shows fluid service is justified; never mix with Toyota Type T-IV Fitment/availability: 2007-2018 U.S.-market Yaris 4-speed automatic branches whose VIN-specific owner's or service manual calls for To…
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
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.
Common Symptoms
- Shudder at 35-50 mph
- Vibration during light throttle
- Feels like driving over rumble strips
- Shudder goes away with more throttle
How to Fix
Change transmission fluid using Toyota WS fluid only. Perform a drain-and-fill (not flush) 2-3 times over 10,000 miles to fully exchange fluid. Toyota TSB T-SB-0084-16 addresses this with a software update. If shudder persists, torque converter replacement may be needed ($1,200-2,000).
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Toyota Genuine ATF WS one-quart bottle
correct-spec drain/refill consumable after diagnosis, not a guaranteed converter repair Fitment/availability: Toyota World Standard ATF; use only after confirming the exact 4Runner transmission specification and required service quantity…
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Owner tips & cautions
- TipDIY repairs can save significantly - dealer charges $1,200-2,000 but DIY costs are typically 50-70% less
- TipGet a proper diagnosis before replacing parts - similar symptoms can have different causes
- TipSearch Toyota 4Runner forums and owner groups for real-world experiences and DIY guides
- TipGet multiple quotes from independent mechanics - dealer prices can be 2-3x higher for the same repair
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 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 it is documented across 4 models: Tacoma, Highlander, Yaris, 4Runner.
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 Toyota?
Published repair estimates on Toyota range from $150 to $2,500 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.