P1740: How to Diagnose & Fix — Torque Converter Clutch System Fault (Manufacturer Specific)
2 vehicles · 2 makes · $1,800-$8,000 repair
How to diagnose and fix P1740: most-reported vehicles
Ranked by owner reports. Each card gives the symptoms, how to confirm the cause, the fix, parts and sources for that vehicle.
Ford F-150 · 1997–2008
The 4R70W (and later 4R75W/4R75E) 4-speed automatic behind the 4.2L V6 and 4.6L/5.4L V8s is prone to several high-mileage failures: a broken reverse (cast) band that produces a loud POP and loss of reverse; a cracked forward-clutch drum snap-ring groove on 2005+ units causing loss of ALL forward gears while reverse still works; worn overdrive band and clutches causing slipping; and solenoid-body/servo wear causing harsh or erratic shifts. Failures accelerate under towing/heavy loads and when fluid changes are neglected.
Common Symptoms
- No reverse engagement or a loud pop then loss of reverse
- Truck has reverse but no forward movement (2005+ forward-drum failure)
- Slipping or flaring on 1-2/2-3 upshifts
- Delayed or harsh engagement into Drive
- Overdrive slipping under load
- Limp mode (stuck in one gear)
How to Fix
Diagnose fluid condition (burnt smell, metal), line pressure, and DTCs before teardown. Repair typically means a full rebuild with upgraded forward drum/snap ring, new bands, updated solenoid pack, and torque converter; add an auxiliary transmission cooler if the truck tows. Regular fluid/filter service (Mercon V) is the main preventive measure.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Forward clutch drum (upgraded, forged) — Sonnax Smart-TechCross-refSonnax 76654-01K, TCS Smart-Tech 76654-01K, Sonnax 76655-01K (high-capacity kit version)$250–$300
This is the fix for the 2005+ failure mode described in the issue: the OE stamped drum cracks at the snap-ring groove and the truck loses ALL forward gears while reverse still works. The Sonnax replacement is one-piece forged with a deep…
- Auxiliary transmission oil cooler (tow duty)Cross-refTru-Cool Max LPD4739 (40,000 GVW, low pressure drop, thermal, Tru-Cool LPD47391 / OC-4739-1, Hayden / Derale stacked-plate equivalents$100–$165
Universal-fit add-on, not a year- or engine-specific part — this is the 'add an auxiliary cooler if the truck tows' half of the documented fix, and the cheapest insurance against a repeat failure.
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Sources for this issue (2)
Nissan Rogue · 2014–2018
The second-generation Rogue uses a JATCO continuously variable transmission (RE0F10x family) that is widely documented to judder/shudder during light acceleration (typically 25-45 mph), exhibit a 'rubber band' rubbery hesitation from a stop, overheat into limp mode with sudden loss of power at highway speed, and in many cases fail completely before 100,000 miles. CarComplaints lists 111+ power train complaints for the 2014 model alone (severity 10/10), and Nissan accumulated well over 1,000 transmission-related NHTSA complaints across the generation. A class action (Stringer v. Nissan / related Rogue-Pathfinder-QX60 settlement, final approval March 2022) extended the CVT warranty on 2014-2018 Rogues from 60mo/60k to 84mo/84k miles and provided repair reimbursement.
Common Symptoms
- Shudder or judder during light acceleration 25-45 mph
- Rubber-band feeling / hesitation from a stop
- High RPM with little forward movement
- Sudden loss of power / limp mode at highway speed
- Transmission overheating warning
- Jerking or stalling at stops
How to Fix
Check for an active CVT warranty extension (84mo/84k from original sale on 2014-2018 Rogue) and have the dealer replace the CVT at no charge if eligible. Out of warranty, a remanufactured unit at an independent shop typically runs lower than a new OEM CVT at the dealer. A CVT software/valve-body update or fluid service (NS-3 fluid) can mitigate early judder; codes P17F0 (CVT judder) and P17F1 (chain slip) confirm the failure mode. Submit class-action claim paperwork for reimbursement of prior CVT repairs.
Call to confirm they can assess your vehicle and perform the stated work. Search results do not confirm qualification, eligibility or coverage.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Genuine Nissan NS-3 CVT fluid quart 999MP-CSHNS3
2014-2018 Rogue T32 CVT applications specifying Nissan NS-3; verify VIN and calculate quantity from the exact service operation.
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Sources for this issue (3)
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P1740 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 P1740 mean?
P1740 stands for "Torque Converter Clutch System Fault (Manufacturer Specific)." This is a manufacturer-specific transmission code indicating a fault in the torque converter clutch (TCC) system. The torque converter clutch mechanically locks the engine to the transmission at cruising speeds to reduce slippage and improve fuel economy; the computer controls it with a solenoid and monitors whether it locks and unlocks correctly. This code sets when the system doesn't behave as expected — for example, the clutch fails to lock, slips, or the control circuit is faulty. Symptoms can include shudder, poor fuel economy, higher RPM at cruise, or a transmission that won't lock up.
What are the most common causes of P1740?
The most common causes of P1740 are: Faulty torque converter clutch (TCC) solenoid, Worn or failing torque converter, Low, dirty, or contaminated transmission fluid, Valve body wear or stuck valve, Damaged TCC solenoid wiring/connector, Internal hydraulic pressure loss, Faulty transmission control module (TCM). The specific cause varies by vehicle.
How much does it cost to fix P1740?
Repair costs for P1740 range from $1,800 to $8,000, depending on the vehicle and root cause.
Which vehicles are affected by P1740?
Au7o has documented P1740 across 2 vehicle models from 2 manufacturers: Ford, Nissan.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.