I have a 2005 Pontiac Vibe with 55000 miles. About 3 months ago the check engine light came on and the car was shifting hard between 1st and 2nd, so I took it to the dealer. When I picked it up they said nothing came up on the scanner but the mechanic said to place the transmission pressure control valve soleniod. I had that replaced by a local transmission shop. Now two months later the light is back and so is the hard shifting. The transmission shop ran the check engine light but said no code came up. I don't want to replace the solenoid again because I think the check enginee light will just come back on again three more months from now. Any ideas? (The vibe is the base model with an automatice transmission.)