Replaced the evap core for the a/c... had to tear out the dash.. reinstalled everything... now it cranks.. wont start...odo is saying no bus.. chkd all connections..trans indicator keeps scrolling

If your battery is older than five will stop accepting a charge...newer batteries are made from a tin/antimony alloy and do not last but five years...A new one will have the full 13.5 volts....though 12 Volts may be okay and start you just fine, will cause the alternator to work overtime....yours sounds like a grounding problem...undo the black 1/0 cable what attaches to the frame and wirebrush the frame and the lug to assure the needed 300 or so Cold Cranking Amps...inextricably they share THIS ground connection with the ECU and other delicates that do not like varying amperages available and varying voltages and begin to give problems~....false CEL on account of undervoltage...etc.~

From what ive been reading?...everyone has been replacing the PCM?...And the problem goes away...

No bus in the cluster means no B+ circuit from the PCM there is either a pinched wire under the steering column or a broken or shorted wire.

these fully encapsulated modules usually do not go bad, but succumb to undervoltages and bad ground~ If you bench tested the PCM, BCM, or ECM you'd find them to operate normallly, but when installed are not getting sufficient ground to operate correctly~

A powertrain control module, abbreviated PCM, is an automotive component, an electronic control unit (ECU), used on motor vehicles. It is generally a combined control unit, consisting of the engine control unit (ECU) and the transmission control unit. On some cars, such as many Chryslers, there are multple computers: the PCM, the Transmission Control Unit, and the Body Control Module, for a total of three separate computers as an example. These automotive computer's are generally very reliable. The PCM commonly controls more than 100 factors in a car or truck. There are many hundreds of error codes that can occur, which indicates that some subsection of the car is experiencing a problem. When one of these errors occurs, usually it will turn on the "check engine" light on the dashboard. The PCM is one of potentially several onboard computers, or essentially the "brain" of the engine control system. When the "brain" does not function correctly, neither will the engine or anything else that the microprocessor controls, which may include the charging system, transmission, various emission controls and communications with other onboard control modules. The PCM should be replaced only when it is diagnosed to be defective.

...that was helpful....NOT~