I only know three things and the minimum throttle relearn is one of them. Mitsubishi and Chrysler have a lot in common, and this is one of those things. Now you're into something I'm not familiar with. Chrysler's "limp mode" is to default to second gear and stay there. That pertains to the transmission. As far as how they indicate that to you is different on various models. On older cars the Check Engine light turned on and the diagnostic fault code was # 700 which just meant there was another diagnostic fault code stored in the Transmission Computer. You need a scanner that can access that computer to read the codes.
By the late '90s the indication of limp mode was all the shift indicator lights on the instrument cluster for every gear lit up at the same time. To get it out of limp mode you have to turn the ignition switch off, then restart the engine.
There isn't much that can go wrong with a torque converter, and of the hundreds of potential fault codes, only a few relate to it. Typical failures include fluid leakage, a vibration at highway speed, and a failure of the clutch to lock up. The clutch only locks up above about 45 mph and in fourth, and maybe third gear, and only after the engine is warmed up. If you have a tachometer on the dash, you can verify the lockup clutch is working by tapping the brake pedal. With the engine warmed up, drive at highway speed, and hold the accelerator pedal perfectly steady. Tap the brake pedal momentarily with your left foot. You should see engine speed pick up about 200 rpm, then drop back down a couple of seconds later. If you don't have a tach, you can usually hear the increase in engine speed too.
If there is a problem with the transmission, you'll need to have a mechanic connect a scanner to read the fault code(s). Sometimes you can get an idea of what kind of problem there is by observing when it goes to limp mode, or fail safe mode. If you start the engine, shift into "drive", and it starts out in second gear right away, (at least for Chrysler products), it's usually electrical in nature and most commonly due to a failed sensor. If it starts out in first gear like it's supposed to, then bangs back to second gear during or right after a shift, it's usually due to slippage in a clutch pack. On the Chryslers the mechanic can read the "clutch volume index", (CVI) with the scanner. That's a set of four numbers corresponding to the volume of fluid it takes to apply each clutch pack. With those numbers an experienced transmission mechanic can tell how much life is left in each clutch pack. When a certain number is reached, slipping can be expected, and that will trigger a fault code and send the system into limp mode. The transmission has to be rebuilt to take care of that.
Friday, November 7th, 2014 AT 2:12 PM