P0740 on Mercury
Torque Converter Clutch Circuit Malfunction
P0740 on Mercury vehicles indicates torque converter clutch circuit malfunction. Au7o has documented this code across 1 Mercury model — most commonly on Cougar. 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.
Common Causes of P0740
- •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
P0740 on Mercury by Model
Mercury Cougar(1 issue)
- CD4E Automatic Transmission Failure (8th Gen)1999-2002
NHTSA communications establish several distinct CD4E conditions on 1999-2002 Cougar vehicles: no-forward engagement in 605229 and 6091763, 1999 ring-gear side loading of the forward-clutch snap-ring retainer in 607645, intermittent loss of first and second gears with P0758 or P0740 in 619324, and harsh or delayed shifts after speed-sensor service in 630631. These records support the generic CD4E problem identity but not one universal valve-body or drum cause.
Looking for P0740 on a different make?
View P0740 across all makes →Frequently Asked Questions
What does P0740 mean on Mercury?▼
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 Mercury specifically, this code is documented across 1 model.
What causes P0740 on Mercury vehicles?▼
Common causes on Mercury: 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. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0740 on a Mercury?▼
Repair costs vary widely depending on the root cause and specific Mercury model.
Which Mercury models have P0740 documented?▼
Au7o has documented P0740 on 1 Mercury model: Cougar.