Chrysler Repair: Error codes 12, 13?, chrysler new yorker, fuel mixture

Question
I am looking for the Error codes for a 88 Chrysler new yorker. after cycling the ignition 3 times to read the check engine light code read out i got code 12,13 and 55 for end of codes ..I do not know what the 12 and 13 are for , Can you help me out ?

Answer
Hi Steve,
The 12 means that sometime in the past 50-100 key on-off cycles the battery power seen at the engine controller was turned off. If you don't recall disconnecting the battery you might check the clamps and cables attached thereto.
Thre 13 means that the voltage signal of the manifold absolute pressure sensor doesn't change between ambient and when the engine is running, e.g. it is not sensing any difference in the pressure. It could either be that the vacuum hose from the manifold to the sensor is disconnected/cracked, or that the sensor isn't working. On the 3.0 liter engine it is mounted on the generator bracket, while on the 4 cyl engines it is mounted on right shock tower. It is responsible for the fuel mixture so you may have noticed a degradation in the engine function.
Roland