Originally Posted by mrherrera
My CEL is on,i took it to autozone and they gave me the code P0740,but they didn't know if this was a bad sensor or i need to fix my tranny,can you tell me what this code is suppose to mean?
DTC P0740: Problem in Lock-up Control System
NOTE:
Record all freeze data before you troubleshoot.
Keep replacement solenoid valves on hand:
Torque converter clutch solenoid valve/shift solenoid valve A
A/T clutch pressure control solenoid valves A and B
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 .
5) Using the scan tool, check to be sure that the engine coolant temperature is in 176°F (80°C) and above .
6) Drive the vehicle at 55 mph (88 km/h) constantly formore than one minute .
7) 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.
Doesn't look good :happysad: Hopefully #3 and 4 fix it.