P0740 on Acura: How to Diagnose & Fix
Torque Converter Clutch Circuit Malfunction
2 Acura models · 2 documented issues · 1 critical · $150-$3,500 repair
P0740 on Acura by model: symptoms, diagnosis and fix
Third-generation MDX models with the ZF 9-speed automatic suffer from torque converter shudder during light throttle acceleration between 30-50 mph. The lockup clutch in the torque converter vibrates as it engages, creating a sensation similar to driving over rumble strips that many owners mistake for an engine misfire.
Common Symptoms
- Vibration/shudder at 30-50 mph under light throttle
- Sensation like driving over rumble strips
- Shudder disappears under hard acceleration
- Vibration felt through seat and steering wheel
- Transmission slipping sensation
How to Fix
Update the TCM software to the latest Acura calibration that modifies torque converter lockup strategy. Perform a complete ATF drain and refill with Honda DW-1. If shudder persists after software update and fluid change, the torque converter assembly must be replaced.
Owner tips & cautions
- TipGet the TCM update first — it resolves about 70% of cases for free under warranty. If the shudder returns after 10,000 miles, the torque converter needs replacement. Do not let the dealer just change fluid and send you home.
The Honda BAXA/MAXA 4-speed automatic in the Integra is notoriously sensitive to fluid condition and shift-solenoid contamination. Solenoid A/B failure causes flashing D4 light, harsh or missed 2-3/3-4 shifts, loss of power in D4/D3, and sometimes speedometer drop-out. Integra often faces delayed or missed shifts and manual downshifting difficulties in automatic transmissions. Shifting problems in the 1998 Integra's automatic transmission can stem from a clogged transmission filter or screen restricting fluid flow. This causes poor hydraulic pressure, leading to missed 4th gear shifts and failure to downshift. While driving, the D4 suddenly lost almost all power, wouldn't shift, and the speedometer stopped working. Codes returned were Automatic Transaxle FI A circuit failure and ELD error.
Common Symptoms
- flashing D4 indicator
- harsh 2-3 shift
- no 4th gear
- loss of power in D4/D3
- speedometer intermittent
- shift hold in gear
How to Fix
Drain-and-fill with Honda ATF-Z1/DW-1 (NEVER use generic Dexron — it will destroy the clutches). The transmission fluid in the Integra 4AT's are supposed to be changed every 3 years/36,000 mi. It can cook and wear out just like the oil in your engine. Pull codes with a Honda jumper or scan tool; the lock-up and shift solenoids are external, three-bolt parts accessible from the engine bay and often just need cleaning. A screwed up lock-up solenoid will give you a general CEL #70 (Automatic Transaxle); the solenoid is totally accessible from the engine bay and costs less than $200 to replace. It's held in place by three bolts.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Genuine Honda 08200-9008 ATF DW-1 (ATF-Z1), 2 quarts
Repair fluid Honda/Acura automatics requiring ATF-Z1 or DW-1; the issue is specifically the Integra four-speed automatic.
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Owner tips & cautions
- WarningUse only Honda ATF-Z1 or DW-1. Generic ATF causes shift flare and premature failure.
- TipPull the specific solenoid code before condemning the transmission — a $150 solenoid often fixes it.
Sources for this issue (2)
P0740 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 P0740 mean on a Acura?
P0740 stands for "Torque Converter Clutch Circuit Malfunction." This code indicates a malfunction in the torque converter clutch (TCC) circuit of an automatic transmission. The torque converter clutch mechanically locks the engine to the transmission at cruising speed to improve fuel economy and reduce slippage, and it is engaged by a solenoid controlled by the transmission computer. The code sets when the computer detects an electrical problem with the clutch circuit or sees that the clutch is not engaging or holding as expected. Common signs include slipping, shuddering, poor fuel economy, or stalling when coming to a stop. On Acura it is documented across 2 models: MDX, Integra.
What are the most common causes of P0740?
The most common causes of P0740 are: Faulty torque converter clutch (TCC) solenoid, Low or contaminated transmission fluid, Wiring or connector fault in the TCC circuit, Worn or failing torque converter, Valve body wear or sticking valves, Internal transmission electrical short, Faulty transmission control module. The specific cause varies by vehicle.
How much does it cost to fix P0740 on a Acura?
Published repair estimates on Acura range from $150 to $3,500 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 P0740 on a different make?
View P0740 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.