Her is the definition and a list of possiable causes.
Code P1740-Torque converter clutch did not lock up when the PCM sent the command. Enabling conditions: No engine or transmissions
codes are present, vehicle speed was under 70 MPH, TPS was under 33% open. When the PCM commanded the torque converter to lock, no change was detected in engine speed. Blocking action: This code can block the following monitors: none.
Testing: Check torque converter solenoid
for proper operation.
P1740 TCC O/D SOL PERFORMANCE (GAS)
Theory of Operation
The Torque Converter Clutch (TCC) Solenoid is used to engage the TCC which improves fuel economy
The Torque Convertor Clutch (TCC) and Overdrive Clutch (OD) will be tested each time the PCM requests TCC engagement in 3rd gear and OD.
The DTC will set if the expected RPM drop is not achieved while attempting to engage TCC or OD. This indicates a malfunctioning torque convertor or overdrive clutch.
* ENGINE DTCS PRESENT
* TRANSMISSION DTCS PRESENT
* TRANSMISSION TEMPERATURE TOO COLD
* OIL PAN CONTAINS EXCESSIVE DEBRIS
* 3-4 SHIFT SOLENOID
* SHAFT OR SEAL DAMAGE
* TCC SOLENOID
* TORQUE CONVERTER