DTC P0740: PROBLEM IN LOCK-UP CONTROL SYSTEM
1. Check whether the scan tool or the HDS indicates another code.
Does the scan tool or the HDS 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 (see Pressure Test ).
Is the line pressure within the service limit?
YES - Go to step 3.
NO - Replace the transmission.
3. Replace torque converter clutch solenoid valve
4. Replace A/T clutch pressure control solenoid valve C (see A/T Clutch Pressure Control Solenoid Valve C Replacement ).
5. Clear the DTC with the scan tool or the HDS.
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 under the same conditions as those indicated by the freeze data, or at 55 MPH (88 km/h) with very steady throttle for more than 1 minute.
8. Recheck for code P0740. Does the scan tool or the HDS indicate code P0740? YES - Remove the torque converter and inspect the O-ring. If the O-ring is missing, replace the O-ring. If the O-ring is damaged or OK, replace the transmission and torque converter. NO - The system is OK at this time.
Thursday, December 11th, 2008 AT 11:09 AM