Transmission clunking causing transmission to lock into third gear, also check engine light on with code P0700

Hi,

The code you have is related to the transmission, so I suspect that is where you are hearing the noise. Here is the issue. The P0700 is more or less a generic code that sets simply to indicate there is an issue but further diagnostics are needed. A scan tool that can read all codes should be used in this situation because I feel the problem/code will be stored in the transmission control module and most basic scan tools can't read those codes. Actually, a scan of the entire can bus system should be completed. Here is a video that shows it being done:

https://youtu.be/InIlnsjOVFA

In this case, what is called "freeze frame" data should be reviewed before the code is cleared. Freeze frame data is just what it sound like. It is a snapshot of how several different sensors reacted when the fault was set. By reviewing that, it should help point us in the right direction.

Let me know if this helps or if you have questions. The vehicle should be further diagnosed before anything is repaired or replaced simply because we don't know yet what part of the transmission or transmission control module is causing the problem.

Let me know.

Joe

Hi,

To be honest, it would be odd for both a solenoid and TCM to go bad at the same time. Did they tell you what solenoid or solenoids?

As far as price, because of the model year, I don't have part information. However, I can't imagine it taking more than an hour to replace and program. As far as the solenoids, can you let me know which ones they told you need replaced?

Joe

P0700 is a generic -I have a problem in my transmission- code. It pops up only to tell a shop to scan the transmission control system for the real code.
P0743 is the actual problem code and it is a circuit code, which means the TCM sees there is a problem with the converter clutch solenoid or it's control wiring. Either shorted, open or it's getting the wrong feedback from the solenoid. It is very likely the wiring or connector for the clutch solenoid. Testing if it is the solenoid is easy and requires a simple volt ohm meter. You start by unplugging the transmission connector and measuring the resistance between the two indicated pins in the connector on the transmission. You should see 3.5 ± 0.2 ohms between those pins if the solenoid is good. If it tests bad then replace the solenoid pack, if it tests good, then inspect the wiring harness connectors and the harness back to the TCM. It doesn't take much to cause an issue.