P0744: How to Diagnose & Fix — Torque Converter Clutch Circuit Intermittent

The NV200's Jatco CVT transmission is particularly prone to failure when used for commercial delivery work, which is the vehicle's primary purpose. The constant stop-and-go driving and heavy loads accelerate CVT belt wear and valve body degradation. Many owners report failure between 60,000-100,000 miles. Symptoms include jerking during acceleration, delayed shifting, and eventually complete loss of drive.

C3s fitted with Citroen's automated-manual gearboxes — SensoDrive on the C3 I, then EGS6/ETG6 on later e-HDi and PureTech cars — suffer well-documented failures of the electronic clutch actuator, gear actuator and gearbox ECU. Worn actuator motors and clutch-position adaptation errors cause violently jerky gearchanges, refusal to select gears, gearbox warning messages with the box locked in gear (limp mode), and in some ECU failures a car that will not start. Specialist rebuilders describe the actuator and ECU faults as inherent design weaknesses, and repairs at a dealer can run from several hundred to several thousand pounds.

The B17 Sentra's Jatco CVT (JF015E / CVT7, RE0F11A) uses a torque converter with a lockup clutch, and P0741 is set when the TCM sees the converter clutch failing to lock (input-shaft vs converter speed difference exceeding threshold). On these Nissan CVTs the lockup solenoid lives in the valve body, and the Jatco valve-body bores are prone to wear that causes pressure leakage and sticky solenoid/valve movement; degraded or overheated CVT fluid full of clutch material makes it worse. Drivers commonly feel a shudder/judder at light throttle, and on this transmission P0741 frequently appears alongside related lockup/judder codes such as P0744 and P17F0.

The TA60 radiator has the automatic transmission cooler built into the bottom tank, with coolant and ATF separated only by a thin internal wall. That wall cracks with age and thermal cycling, letting coolant push into the transmission circuit. The resulting pink, milky ATF - owners call it the strawberry milkshake - swells and delaminates the clutch friction material and destroys the RE5R05A within a few hundred miles of driving. The failure is frequently silent until shifting goes bad, and the same rupture can also push ATF into the cooling system. The factory spring clips on the cooler line-to-radiator joints are a second, separate leak point.

The Altima's JATCO continuously variable transmission (RE0F10-series on the 2.5L, RE0F09-series on the 3.5L V6) uses a torque converter with a lockup (TCC) clutch, and P0741 sets when the TCM detects an rpm slip mismatch showing the lockup clutch is not engaging as commanded (stuck off). On Altima CVTs the code is commonly driven by degraded/overheated CVT fluid, a worn or sticking lockup control solenoid, or a valve body whose bores wear and leak line pressure so the TCC can't hold. On earlier RE0F10A units (notably 07-08) the valve body is prone to internal leakage, and a Nissan bulletin directed control valve (valve body) replacement plus TCM reprogramming when P0744 and related codes appear; on the 2013-2014 V6, a lock-up judder bulletin (NTB13-086) can lead to torque converter or full CVT replacement. Drivers feel a shudder or judder under light acceleration (roughly 25-45 mph), rubber-band hesitation, higher-than-normal cruising rpm, and sometimes a slight surge as the converter fails to lock.