code 51

[shmed]

went out to start the gn today, and the battery was dead.
the car has been sitting about 3 weeks.
charge it up and now it hardly runs!
tried resetting the ecm no good.

heres what its doing.
start, barely idle, doesnt matter where the throttle is put, then stalls. restart nope wont restart, hafta reset the ecm then it just does it again.

its showing a code 51 on my sm2,

and when it is running its smoking like its on fire. pure fuel.
help?

 

[turbo buicks]

CODE 51

Trouble Code 51 indicates that the ECM sensed a fault in the PROM.

When the PROM was initially created, a checksum number representing the total of all the cell values was also stored. The ECM uses this checksum as one way to determine if the contents of any cell has changed. A Code 51 causes the ECM to enter Back-Up mode which uses the CALPAK for default sensor values.

The conditions for setting this code are:

power has just been applied to the ECM, and
the calculated checksum does not match the stored checksum.
- or -
the engine was just started, and
either of two specific PROM locations do not contain the expected value. (One location should have 1's in the odd numbered bits and the other has 1's in the even numbered bit positions.)

Typical causes for this code include:

1) Incorrectly installed PROM module
2) Defective PROM module
3) Defective ECM