P0740 on Chevrolet: How to Diagnose & Fix
Torque Converter Clutch Circuit Malfunction
4 Chevrolet models · 4 documented issues · $150-$3,500 repair
P0740 on Chevrolet by model: symptoms, diagnosis and fix
Both the 8-speed and 10-speed automatic transmissions can develop a shudder during light acceleration. This torque converter clutch issue is widespread across GM trucks. Multiple TSBs have been issued addressing this concern.
Common Symptoms
- Shudder during light acceleration
- Vibration at 25-50 mph
- Harsh shifts
- Hesitation when accelerating
- Shudder goes away under heavy throttle
How to Fix
Perform the GM fluid exchange to Mobil 1 Synthetic LV ATF HP per bulletin 18-NA-355 (no additives; mixing other fluids or additive packages reduces effectiveness). The bulletin repair is covered under the powertrain warranty when within coverage. Multiple fluid changes may be needed. Torque converter replacement in severe cases.
Sources for this issue (1)
The 8L45 8-speed automatic transmission can develop a shudder during light acceleration, typically between 25-50 mph. This is caused by torque converter clutch issues, similar to problems in other GM vehicles with this transmission family.
Common Symptoms
- Shudder during light acceleration
- Harsh or jerky shifts
- Vibration between 25-50 mph
- Transmission hesitation
- Clunk when shifting at low speeds
How to Fix
Perform the transmission fluid exchange in GM bulletin 18-NA-355 using Mobil 1 Synthetic LV ATF HP; do not add other fluids or aftermarket additives. Multiple fluid changes may help. GM has extended warranty coverage for some affected vehicles. In severe cases, torque converter replacement may be needed.
Sources for this issue (1)
Transmission shuddering is common in Equinox models, typically caused by torque converter clutch issues or depleted transmission fluid additives. The shudder is most noticeable during light acceleration between 25-50 mph.
Common Symptoms
- Vibration or shudder during light acceleration
- Shaking between 25-50 mph
- Rough shifting between gears
- Transmission slipping sensation
- Check engine light with transmission codes
How to Fix
Transmission fluid flush and fill (3x flush procedure). Add transmission shudder fix additive (early intervention). Torque converter replacement. Complete transmission rebuild or replacement if severe.
Sources for this issue (2)
The C7 Corvette with the 7-speed manual or 8-speed automatic (the 8L90 automatic arrived for 2015; 2014 automatics used the 6L80 six-speed) can develop an annoying driveline vibration/shudder at low speeds, particularly during gentle acceleration from a stop. The 7-speed manual uses a dual-mass flywheel that can develop chatter. The 8-speed automatic (8L90) shares the torque converter shudder issue with GM trucks. The transaxle-mounted differential and half-shafts can also contribute to vibrations.
Common Symptoms
- Shudder during gentle acceleration from a stop
- Driveline vibration at low speed
- Clutch chatter (7-speed manual)
- Torque converter shudder (8-speed automatic)
How to Fix
For the 8-speed automatic: a transmission fluid exchange with Mobil 1 LV ATF HP. For 7-speed manual: dual-mass flywheel inspection/replacement, or conversion to single-mass flywheel with aftermarket clutch. Half-shaft inspection for worn CV joints. Some vibration at low speed is inherent to the C7 design.
Sources for this issue (1)
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 Chevrolet?
P0740 stands for "Torque Converter Clutch Circuit Malfunction." This code indicates an electrical malfunction in the torque converter clutch (TCC) solenoid 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 open, short, or out-of-range condition in the TCC solenoid circuit. A clutch that is commanded on but slips or won't hold sets a separate code (P0741). Common signs include the converter not locking up (higher cruise RPM and poor fuel economy), a check engine light, or stalling when coming to a stop if the clutch stays applied. On Chevrolet it is documented across 4 models: Silverado 1500, Colorado, Equinox, Corvette.
What are the most common causes of P0740?
The most common causes of P0740 are: Faulty torque converter clutch (TCC) solenoid, Wiring or connector fault in the TCC circuit (open or short), Transmission case connector or internal harness damage, including fluid intrusion, Internal transmission electrical short, Faulty transmission control module. The specific cause varies by vehicle.
How much does it cost to fix P0740 on a Chevrolet?
Published repair estimates on Chevrolet 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.
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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.