jacob83blizz

im getting the obd p0740 code. im having no issue with getting my automatic trans to up shift after second, from what ive read that code saying my clutch circuit wont close. but that doesnt seem the case. ive also read that if that circuit mis fires times or more and it will kick on the check engine light. ive re-set the code and havent had any issues yet ( within the past 8 hrs ).

im wondering could this be a timing belt issue causing the mis fire?

thanks for any help

It Wasn't Me

For starters, you should invest in one of these: http://www.helminc.com/helm/product2...C01&itemtype=N





DTC P0740: Problem in Lock-up Control System
2001 - 2003 Models

(record the freeze data, then proceed)

1. Check whether the scan tool indicates another code.

Does it indicate another code?

Yes - Troubleshoot and repair the indicated code(s). Recheck for code P0740
No - Go to step 2

Note: Don't continue with this until you've resolved the issue(s) causing the other code(s).

2. Drain the ATF through a strainer. Inspect the strainer for metal debris or excessive clutch material.

Does the strainer contain metal debris or excessive clutch material?

Yes - Replace (or rebuild) the transmission.
No - Replace the ATF, then go to step 3.

3. Measure the line pressure. (you'll need a shop to do this, unless you have a Helm's manual and the proper tools)

Is the line pressure within the service limit?

Yes - Go to step 4
No - Repair the hydraulic system or replace the transmission.

4. Turn the ignition switch OFF.

5. Replace the torque converter clutch solenoid valve. (again, shop or Helm's manual and tools)

6. Replace the A/T clutch pressure control solenoid valve A and B. (again, shop or manual and tools)

7. Turn the ignition switch ON, and clear the DTC or reset the ECU by removing fuse #6 from the under-hood fuse box. Wait a minute, then reinstall the fuse.

8. Using the scan tool, check to be sure that the engine coolant temperature is 176 degrees or above. If the coolant is below that temperature, run the engine until it warms up or until the radiator fan comes on.

9. Drive the vehicle at the freeze data speed, or at 55 MPH for more than one minute.

10. Recheck for P0740

Does P0740 come back up?

Yes - Replace the transmission and torque converter.
No - The system is okay at this time. (intermittent issue)



If the timing belt had slipped, you'd be throwing a different code (or codes) and would experience lack of power, misfire(s), etc.

David @ Synchrotech

iTrader: (1)

The P0740 is usually a bad torque converter. I would plan on changing the transmission and converter since the failed converter contaminates the transmission. You should follow the diagnostic steps listed above but it is probably time for a new trans & converter .

jacob83blizz

actually i reset the check engine code through the obd2 reader.
reset it about a week in a half ago. and the light hasnt come back on.
im thinking the torque convertor just missed fired. from some info i got at my local transmission shop, if it miss-fires 4 times within 200 miles it will set the light off. i havent had this problem come up again. this weekend plan on changing the time belt, thinking the timing may have been a cause, but the belt needs replaced regardless.

thanks for the helm link WasntMe. wise in vestment. ill be honest im just now getting into cars past my own; very very basic, repairs. so i hope you dont mind i might be shooting a good bit of dumb questions your way.

It Wasn't Me

Glad it was an intermittent issue. Best of luck with it.

nsrhonda89

The light might come back. I was able to put 60k on my 2001 acura 1.7 el with the same P0740 code. I changed the tranny fluid twice a year though. If you find the light is coming on more frequently then its time for a rebuild and replace the torque converter.