93 cherokee error codes 12 and 14

My jeep is starting then stalling (more like shutting off) within 1-2 seconds. Someone suggested checking the error codes, so I did and it has 2 of them:

:arrowr: Code 12 - Direct battery input to PCM was disconnected within the last 50 Key-on cycles.

:arrowr: Code 14 - MAP sensor input above or below acceptable voltage.

can someone give me a brief explanation of what could cause these codes and how to fix (or track down) the problem?

Thank you very much! :cheers:

12 is informational telling you the battery has been disconnected or lost power recently. If you haven't disconnected the battery recently, you need to find out why the computer THINKS you have.

14 means just what it says. Not getting the correct input signals to the computer. Can be the map sensor, the vacuum line leading to the map sensor, the connector, or the wiring of the map sensor circuit.

I'm pretty sure a 93 has a fuel pump ballast resistor, so although the map sensor code is a likely diagnostic, do not forget to check that resistor, and bypass it to test, since that resistor failing will also cause the same kind of shutdown.

Thank you all for your suggestions, this issue has been resolved in my other thread:

http://naxja.org/forum/showthread.php?t=1060387