Car will start if using a jumper cable.. but acts like theres no power to the bater when i shut it off and try to restart it... fault code flashed 12 and then 55 on the check engine light...the haynes manual says that means this Code 12.................Problem with the battery connection. Direct battery input to PCM disconnected within the last 50 ignition key-on cycles. and this Code 55.................Completion of fault code display on CHECK ENGINE light. This is the end of stored codes so does that mean my battery is shot? the cables? the alternator? what is wrong and what do i need to do to fix it? any help would be appreciated

NEEDS SERVICE FOR SURE THOSE 2.
OR
battery cables tight and clean, jumper cable start it if starter is dead?
CHECK ALL FUSES, CAB/BAY
SCAN THE pCM OBD2 PORT FOR DTC ERRORS, AND SRS TOO
MAY BE THE BATTERY (UNDER HOOD)_ IS WEAK OR A FAILING ALTERNATOR.
'COMPLETELY SHUT DOWN MEANS ENGINE STALLED?
WELL IF THE BATTERY DIES, THE EFI DIES AND IF IT DIES ENGINE STALLS AND MOST TIMES WILL NOT CRANK UP AGAIN.
SURELY THE BATTERY IS NOT 12 YEARS OLD ,NO WAY DO ANY LAST THAT LONG, 10 MAX SEEN BY ME. 5 DECADES .
if will not crank now, jumper cable start it. or take the battery to a shop and get it charged and load tested.

if battery is new'ish clean the lugs and make them tight.

IS THE STARTER DEAD (KEYED TO ,START,CRANK)?????
TELL MORE FACTS, END TO END,
IF IT ALMOST STALLS AGAIN CAN YOU PREVENT THE STALL WITH FAST ACTING RIGHT FOOT?
these are just some ideas based on incomplete inputs
I can not see all the acts end to end.
for sure any restart actions.

I do suspect low battery due to 3 majors in the car failing,
EFI, SRS BAGS AND STEERING.
A DC POWER LOSS.

There are codes. You would have to have them read when it happens. And not to shut off the car until the codes are read. I would bet the codes would all be U codes, lost communications. Caused by a bad ground wire. Your main three are the battery to engine, battery to body and engine to body.

Check battery posts and terminals are shiny clean ,lead terminals and posts often get a black coating on them it acts as a insulation so make sure they are clean, then check the earth is tight where it bolts to the frame. the other cable nuns to the starter solenoid check voltage at terminal .12 volts . with a jumper wire touching the small starter terminal flash the large starter terminal, the solenoid should click in and work the starter. if not it may be at fault. also some cars have a earth coble that connects the frame to the engine ,often fitted from the transmission to the frame.

what engine is in there.
most have be swapped by now on these old cars.
still sammi?
still EFI?
did you drive with the EFI , diagnositic jumper inserted yet?
and see if it flashes code 12 (good) or some other code or many other bad codes?
if no codes ever shown but 12s
id monitor fuel pressure driving.

Hello ipontrees40: My name is Roger and I will help with your answer. Locate the ECM on the left kick panel. There will be a lead of wires that has 3 leads hanging. Connect the white and black wires together. Turn the key on and observe the check engine light. Should flash i sequeince of 12, will flash once pause followed by two quick flashes. This is code 12. Any codes after the 12 will be stored codes. Be sure not to start the engine when checking the codes. Should you start the engine you may not receive the correct information. The codes will be read as slow flash followed by a long pause followed by quick flashes. For examle a code 42 would be 4 slow flashes followed by 2 quick flashes. After the computer has read all storer codes it will go back to code 12. After you repair the problem you can clear the codes by either removing the negative battery cable or #3 fuse for ten seconds. Remember just because there is a code does not mean that part is bad. You need to follow basic trouble shooting to make a propper repair. Just replacing parts becomes expensive. I attatched a picture of the jumper wires to the computer to help in identifying them .
Should you need further help please just ask. Please rate the answer. Thank You for using Fix Ya. Roger

This is straight from Haynes Repair Manual for 1989-1997 Isuzu Amigo/Rodeo/Honda Passport (book # 47017:
The 12 pin Assembly Line Data Link (ALDAL) terminal is located under the dash on the driver's side on 3.1L engines. To retrieve the trouble codes, connect a jumper wire to terminals A and B. It may be covered with a plastic cover. They suggest using a paper clip to jumper the two terminals-then turn ignition switch to ON position (NOT ENGINE START). Check engine light on dash will flash-one flash-a pause-then two short flashes-indicating code 12-diagnostic mode. After self checking-if there are any trouble codes-the light will flash proper codes using mentioned method.Note the flash code then call a shop with your info for what ails your Rodeo.

check your air filter, may have picked up dust and air flow is restricted

Your going to have to pull some code to help you with the problem. 
On board diagnostic (OBD) was designed on vehicles equipped with electronic fule injecton so you can generally retrieve the codes yourself. No need buying a scanner or running to any parts stores to check the ENGINE LIGHT. This system is called obd1 and applies to most vehicles made before 1995 for domestics and 1993 on imports. 

For GM domestic vehicles made before 1995, the diagnostic connector is located under the dash panel by the driver side. To get the check engine codes to flash in your dash panel, use a jumper wire or a paper clip and connect terminals A and B of the diagnostic connector. 
Turn your ignition key on with engine off and the codes should start to blink. All codes should start with code 12 which is one long flash followed by 2 short flashes. 
This code 12 means the diagnostic system is normal and will repeat itself continuously if there are no trouble codes. Otherwise, code 12 will flash 3 times before flashing the fault codes.

Most of the codes can be erased or cleared by disconnecting the battery negative terminal for 1 minute and reconnect. Just make sure to check your service manual in case you have electronic equipment such as radio or clock that needs reprogramming in which battery disconnection is not recommended. 
Finally after performing repairs on the culprit code, always go for a road test to confirm if the problem is fixed.

Here is a link where you can look up the codes your trans am may have to help you find out what's wrong. Good luck and hope this helps. http://chevythunder.com/199295_lt1_trouble_codes.htm

This is an OBD1 module located under the dash:
1st turn off the ignition.
2. Use a jumper wire between the ground terminal "A" top right and the diagnostic terminal "B" second from top right.
3. Turn the ignition to on but DO NOT START ENGINE.
The "Service engine light" soon will flash the code 12 - one flash followed by 2 short flashes. it will repeat then pause followed by yuor trouble codes flash.
Hope this helps

oxygen sensor