It shows a DTC P0780.

Hi mtboaxaca,

P0780 = Mechanical problem in hydraulic control system.

DTC P0780: MECHANICAL PROBLEM IN HYDRAULIC CONTROL SYSTEM.

NOTE:

This code is caused by an electrical circuit problem and cannot be caused by a mechanical problem in the transmission.

Keep replacement solenoid valves on hand;

i. A/T clutch pressure control solenoid valves A, B, and C

ii. Shift solenoid valves A, B, C, and E.

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 for the indicated code(s). Check for DTC P0780 after troubleshooting.
NO - Go to step 2.

2. Turn the ignition switch OFF.

3. Replace A/T clutch pressure control solenoid valve A
4. Replace A/T clutch pressure control solenoid valves B and C

5. Reset the PCM memory by removing the No. 6 ECU fuse (15A) in the under-hood fuse/relay box for more than 10 seconds.

6. Drive the vehicle for several minutes in 1st, 2nd, 3rd, and 4th gears in the D position, and stop the vehicle. Do not stop the engine.

7. Repeat step 6 five times.

8. Recheck for DTC P0780.
Does the scan tool or the HDS indicate code P0780?

YES - Go to step 9.
NO - The problem has been corrected.

9. Turn the ignition switch OFF.

10. Replace the shift solenoid valves A, B, C, and E

11. Reset the PCM memory by removing the No. 6 ECU (15A) fuse in the under-hood fuse/relay box for more than 10 seconds.

12. Drive the vehicle for several minutes in 1st, 2nd, 3rd, and 4th gears in the D position, and stop the vehicle. Do not stop the engine.

13. Repeat step 12 five times.

14. Recheck for DTC P0780.
Does the scan tool or the HDS indicate code P0780?

YES - Go to step 15.
NO - The problem has been corrected.

15. Turn the ignition switch OFF.

16. Remove the transmission, and overhaul transmission hydraulic control system.

17. Install the transmission on the vehicle.

18. Reset the PCM memory by removing the No. 6 ECU (15A) fuse in the under-hood fuse/relay box for more than 10 seconds.

19. Drive the vehicle for several minutes in 1st, 2nd, 3rd, and 4th gears in the D position, and stop the vehicle. Do not stop the engine.

20. Repeat step 19 five times.

21. Recheck for DTC P0780.
Does the scan tool or the HDS indicate code P0780?

YES - Replace the transmission assembly.
NO - The problem has been corrected.

This problem is usually caused by a turbine speed sensor failure.

Here is a video showing you how to replace it.

https://youtu.be/f3bETtCIdxM

Make sure you clear the codes after

https://www.2carpros.com/articles/check-engine-light-clear-codes

Please let us know what you find.

Cheers,

That worked! you guy are the best I love this site. Saved me a ton of $$

MTBOAXACA What part(s) did you replace to fix it.Please answer because I have the same car with similar problems.Thank you.

This post is 14 years old IDK if they will respond.