Thread: 1234 shift solenoid

Hi Ron, i wouldnt suspect shift solenoids to be at fault as they typically work or they dont and also the pcm is in full control of the trans and also has built in electrical/hydraulic diagnostics and there would likely be a shift solenoid code in the pcm history. The best way to track down the problem is to verify shift operation with a scan tool and make sure the pcm is or isnt commanding this shifts to happen when it is not working correctly. There are a lot of possible causes for shift timing issues and since these transmissions are electronic scanning is a must to see what is going on. If you do not have access to a scan tool it would be best to have a shop diagnose the car and if they cannot duplicate the problem then it may mean leaving the car with them for a few days to get it to act up. There are a few valves inside the transmission that can stick and cause shift problems also and typically you will have a 2nd gear start cold but not always. Check out the trans data and shifting info and let us know what you find.