1995 Dodge Caravan need help

The code 12 means that the battery was disconnected within the last 15 ignition switch or power was lost power due to a wiring issue. Are the battery terminals clean and tight? Has the alt light ever come on?

As far as the 55, that only means the computer has completed its check.

Let me know.
Joe

At this point, I would suggest having the logic module checked.

Memory standby power recently lost
Power loss light: Off
Limp-in mode: None

Possible Causes
Battery or power line recently disconnected - This code is normal if the electrical system has been worked on or the battery has recently been disconnected. It will be removed after 15 ignition switch on/off cycles.

Low system voltage, bad battery or battery terminals - If the system recently had a power drop (due to a dead battery or bad alternator), this code will appear. If the battery terminals are bad and the engine was jumped, this code will appear. See the Diagnosing Your Charging System page for more information.

Bad connection or wiring - Check the wiring and connections between the battery, power module, and logic module (or SMEC). Check all fusible links and power connectors to the battery. Clean and regrease any corroded connectors with dielectric grease and repair any shorts.

Diagnostic Method
Trigger Parameters
- Logic module receives power after previously not having power

Results If Component Fails
Fault code 12 is stored. The logic module is basically telling you that it has lost power and will not remember any previously stored codes or engine sensor table data. The code will be removed after 15 ignition on/off cycles and the logic module will use default values for all look-up tables as a starting point until it "learns" the attributes of the engine.

If the computer is losing memory or is not working or getting power, the computer will not work properly.