I have a 92 Civic LX, 1.5L w/AT, question I need help with is getting trouble codes from the ECM by reading the CHECK engine light. This worked before but lately the light stays lit constantly when the service connector is jumped with the ignition ON. Isn''t it supposed to flash any code numbers and then stay off? Is this a problem with the ECM? Could there be an electrical issue? The car has been having speedometer problems lately, like sitting still at a drive thru with speedometer reading 100 mph! It does it when driving too, also causes the torque converter to unlock, but no codes are stored in the ECM.
Would appreciate any input.

Thanks.