What Does P0740 Mean?
The torque converter clutch (TCC) circuit has a general malfunction. The TCC locks the torque converter to the transmission input shaft at highway speeds to improve fuel economy and reduce heat. This code means the PCM/TCM detected an electrical or performance issue in the TCC solenoid circuit.
Common Causes
35%
Failed torque converter clutch solenoid (open or shorted internally)
25%
Wiring or connector issue in the TCC solenoid circuit (corrosion, chafing, broken wire)
20%
Worn torque converter clutch friction material causing slippage
12%
Valve body issue — stuck TCC apply valve or regulator valve
8%
TCM/PCM internal fault or ground issue
Diagnostic Steps
1
Check transmission fluid level and condition — contaminated or low fluid can prevent proper TCC operation.
2
Monitor TCC solenoid commanded state vs. actual TCC slip using live PID data at steady highway speed.
3
Measure TCC solenoid resistance at the transmission connector — compare to manufacturer specification (typically 10-25 ohms).
4
Inspect the transmission connector and wiring harness for corrosion, damaged pins, or chafed wires.
5
If electrical tests pass, perform a TCC apply pressure test to determine if the valve body or torque converter is at fault.
Estimated Repair Cost
$150 - $2,500
Parts + labor, varies by vehicle and location
The torque converter clutch (TCC) circuit has a general malfunction. The TCC locks the torque converter to the transmission input shaft at highway speeds to improve fuel economy and reduce heat. This code means the PCM/TCM detected an electrical or performance issue in the TCC solenoid circuit.
The most common cause of P0740 (Torque Converter Clutch Circuit Malfunction) is: Failed torque converter clutch solenoid (open or shorted internally)
Typical repair costs for P0740 range from $150 to $2,500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
The vehicle is generally safe to drive short distances. Fuel economy will decrease and the transmission may overheat on long drives due to torque converter slippage. Avoid extended highway driving until repaired.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0740 to identify the root cause.
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Quick Info
Category
Powertrain
System
Automatic Transmission — Torque Converter
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
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