Chrysler Repair: 98 Concorde: no shift/no speedo, 4 digit numbers, fuse panel

Question
I have a 98 concorde and after exiting the highway it made a clunk. The transmission after that would not shift and the speedometer was inop also. I have a generic scan tool and found no fault codes. Checked all fuses under the hood and in the main fuse panel by the driver a-pillar. Wondering where I should go from here. Thanks for your help.

Answer
Hi Jeremy,
The lock-up in 2nd gear only is called 'limp-in' mode and the trans controller does this to protect against damage. The loss of the speedo suggests that the output speed sensor on the driver's side of the transmission, at the very rear of the power train, has gone bad. If you get a code readout at an Autozone parts store for free and it shows code 0720 that would corroborate that is the cause. It can be easily r&r'ed from underneath I believe, tightening it to about the same torque as a spark plug. It has a companion sensor (input speed) close to the engine but at the same level on the side of the trans. So don't mistake one for the other.
You might try the ignition key:"on-off-on-off-on and leave in on" doing that in 5 seconds or less elapsed time. Then watch the odometer window to see if it changes to show any 4-digit numbers, preceded by a P, which are the fault codes. But begin in any case with the output speed sensor. When that stops putting out the signal for the speedo it also causes the transmission controller to shut down the trans until it gets that signal so as to shift properly.
Roland