Start by checking for blown fuses under the hood. Often there are current surges when connecting the battery that blows a fuse when there is no problem in the circuit. If the fuse for the Transmission Computer, (EATX), is blown, it won't send the speed information to the Body Computer and instrument cluster. The transmission will also stay in "limp mode" where it stays in second gear.
If you didn't use a memory saver while the battery was disconnected, you might also find the transmission will go to limp mode right after an up-shift. The computer had learned the wear characteristics of the transmission's clutch packs. Until it relearns that information, excessive slippage during shifts can send it to limp mode a number of times. You'll have to turn the ignition switch off and restart the engine to get it out of limp mode.
The engine will likely not want to idle fast enough and will stall unless you hold the gas pedal down a little. The Engine Computer has to relearn "minimum throttle" before it will know when to be in control of idle speed. To meet the conditions for that to take place, drive at highway speed with the engine warmed up, then coast for at least seven seconds without touching the brake or gas pedals.
Sunday, April 10th, 2011 AT 1:26 AM