No vacuum modulator. That's a GM and Ford thing from the past; Chrysler never used modulators. This transmission is computer-controlled and is in "Limp-In" mode. The computer detected slippage between shifts or a sensor problem and defaulted to this mode where it stays in 2nd gear until you turn the ignition switch off and back on.
If the problem is slippage, watch which gear it's headed into when goes to limp-in. Restart the engine, then, the next time you drive it, accelerate faster than normal so you reach a higher speed before it wants to shift into that gear, but let off the gas before it shifts. This will reduce the torque and slippage when it shifts. If you can get it into the next gear without it slipping, you can continue to drive like normal until the next time it slips going into that gear. This is only a temporary measure to get you by for a short time.
If it defaults to 2nd gear at a very low speed, not when a shift is expected, it is more likely to be a sensor issue.
Caradiodoc
Sunday, March 29th, 2009 AT 7:59 PM