DTC P0740: Problem in Lock-up Control System
NOTE:
- Record all freeze data before you troubleshoot.
- Keep these replacement solenoid valves on hand:
- Lock-up control solenoid valve/shift control solenoid valve A assembly
- A/T clutch pressure control solenoid valves A and B
- 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. - Measure the line pressure. See Pressure Tests .
- Is the line pressure within the service limit?
- YES -Go to step 3.
- NO -Repair the hydraulic system as necessary.
- Replace the Lock-up Control Solenoid Assembly set (lock-up control solenoid valve/shift control solenoid valve A assembly. See Lock-up Control Solenoid Valve-Shift Control Solenoid Valve A Assembly Test and the A/T clutch pressure control solenoid valves A and B, see A/T Clutch Pressure Control Solenoid Valves A and B Replacement .
- 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.
- Using the scan tool, check to be sure that the engine coolant temperature is 176°F (80°C) or above.
- Calibrate the engine idle control system in the PCM, see PCM Idle Learn Procedure , and drive the vehicle at 55 mph (88 km/h) for more than 1 minute.
- 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.