Hi, glad to join up
 

Long time owner of 1991 Saturn sl2 that sadly has some structural rust in rear, necessitating replacement. Found and bought a 2001 sc1 with automatic transmission, sunroof (non-functional) and crank windows and manual door locks.
body in good shape with 93900 miles. Check engine light on and flashes when driving. Bluedriver retrieved code B1000, ecu malfunction in body control system, code B1328
Device power #1 circuit high. And code P1336 crankshaft position sensor variation not learned. I did replace the crank sensor with one from my 1991 and the same code keeps recurring. Battery was bad on purchase replaced with a new one with good charge. What is my next step? Is the fault likely in the body control module or the ecu ender the hood?

Flashing SES while driving usually indicates one or more cylinders actively misfiring, so I'm surprised no misfire codes were thrown.....(?)

B1000:

The following snippet is from a post on saturnfans.net, pulled from an FSM for some later gen S series with a BCM:

DTC B1000 - ECU Malfunction
The body control module (BCM) performs an electrically erasable programmable read only memory (EEPROM) checksum as a part of its internal diagnostics as the BCM is operating. When the EEPROM checksum does not equal a predetermined value, the DTC sets. The checksum is the contents of each memory location in EEPROM added together.

DTC Parameters
EEPROM checksum error exists.
The condition exists for 1 second.
Turns ON the service wrench telltale.
Diagnostic Aids
If DTC B1000 is set, clear the DTCs using the scan tool. Cycle the ignition OFF. Wait 10 seconds. Cycle the ignition ON. If DTC B1000 remains a current code, replace the BCM.
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B1328

DTC B1328 Device Power Circuit High

Also have seen it listed as


Ignition 1 Voltage (12 volt VSS) High (general Saturn DTC list on non-Saturn site)
Device Power 1 Circuit High BCM, VCIM (ion red line)
Device power #1 (low current #1) circuit high (GM listing)
Vehicle system voltage is greater than 15.9 volts (another GM specific list)
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If the last one means >15.9V is the "High" the other descriptions are referencing, I'm thinking the voltage regulator in the alternator is toasted and the voltage in the car, which should be held steady around 14.4 while running, is moving around. Overvoltage on supply voltage to electronics can be pretty bad news. So can spikes that occur because of the lack of regulation.

I would start by putting a Voltmeter across the battery and read the DCVolts while idling and while slowly raising the rpms with the throttle. If the voltage drifts significantly from 14.4 ish or gets erratic, my guess would be voltage regulator.

The P1336 pops whenever you install a new crank position sensor. There is a "learn procedure" which I believe requires a GM Tech II service tool. didn't think this was required on 3rd gen S cars, only Ions and up. Apparently, I was wrong. If the code was already present before you replaced the sensor, the previous owner likely replaced it at some point but didn't want to pay to have the procedure done.