2002 Caravan instrument cluster etc

Hello - I have a 2002 Caravan 2.4 Litre 4 cylinder, auto trans, basic model, 97000 miles. Bought from a relative in California and brought to Canada. It has three problems:

1. Erratic speedometer - jumps all around, even when not driving, but not in any predictable way. This problem was repaired just before I purchased it (invoice shows replacement of speed sensors), but it started immediately as I hit the I5 to drive it home to Canada.

2. Occasional, very random, very brief split second cut out or signifcant reduction in power, usually at highway speed. You'll just feel a brief blip, not a miss or rough patch, but as if you'd shut the motor off and right back on (but faster than you could actually do it). Sometimes you'll get a few in a row, then not again for a few hours.

3. Occasional failure to crank. Turn the key on and all dash lights come on, turn to crank and nothing happens - no apparent draw or load on system, no sound of solenoid or starter engaging. Usually if you keep trying it will go and then be fine for weeks or months before it happens again (seems like the ignition switch).

Took it to a mechanic (former dodge dealer mechanic) who could find nothing wrong but had the control module reprogrammed at the dealer because there was a service bulletin for this model. Anyway, no change and he did not charge me.

I scanned for codes with a code reader and none came up. I did the diagnostic on the instrument cluster using the trip odometer reset and got error code 400.1

Any help or direction you can give would be greatly appreciated - especially what the error code means as my manual does not define it.

Thank you for your time.