Cadillac Repair: Service Emissions, warning light, sls

Question
On a 96 SLS with a Service Emissions System warning light, I pressed the off and warmer buttons and got the following codes.  PC0139 Current, PC0603 History, and TC0073 History, and at the end of the cycle PCM? remained on the screen.
Is this a serious problem and your suggestions please.
Thank you for this fantastic service..

Answer
PC0139 Current = Pre-converter slow to respond.

PC0603 History = Battery was disconnected in the past.

TC0073 History = PCM (computer) to Traction Control System (TCS) interface fault.

You will need numerous pictures and directions.

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