P0740

DTC P0740: Problem in Lock-up Control System

NOTE: Record all freeze data before you troubleshoot.

1. Check whether the OBD II scan tool indicates another code.
Does the OBD II scan tool indicate another code?
YES - Perform the Troubleshooting Flowchart for the indicated Code(s). Recheck for code P0740 after troubleshooting.
NO - Go to step 2.

NOTE: Do not continue with this troubleshooting until the causes of any other DTCs have been corrected.

2. Measure the line pressure.
Is the line pressure within the service limit?
YES - Go to step 3.
NO - Repair the hydraulic system as necessary.
3. Replace the torque converter clutch solenoid valve/shift solenoid valve A.
4. Replace the A/T clutch pressure control solenoid valves A and B.
5. Turn the ignition switch OFF, and reset the PCM memory by removing the BACK UP fuse in the passenger's under-dash fuse/relay box for more than 10 seconds.
6. Using the scan tool, check to be sure that the engine coolant temperature is 176°F (80°C) or above.
7. Drive the vehicle at 55 mph (88 km/h) for more than one minute.
8. Recheck for code P0740.
Does the OBD II scan tool indicate code P0740?
YES - Replace the transmission and torque converter.
NO - The system is OK at this time.