Chrysler Repair: Electrical failure?, chrysler dealer, computer cars

Question
HI Roland,


I haven't checked out a TaskMaster at work yet, but I got curious tonight and did the Key "on/Off" thing to see what the check engine light would tell me.  I got 2 codes out of the system.  One was code 12 and the other was code 14.  Code 12, just tells you that the computer or battery have been disconnected resently.  Code 14 is the MAP sensor, voltage below .16 volts or over 4.97 volts.  So, my question about code 14, does this mean the sensor is bad?  Or just that something else is efffecting the voltage?

Computer cars is exactly why I got out of the automobile business.  I wasn't ready for them then (1983) and I not so sure I'm ready for them now.

Thanks again,
Mike


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Followup To
Question -
I have a 1996 Chrysler T&C with the 3.8L engine.  It will die in traffic, just like it ran out of fuel or as if you shut off the ignition switch.  Just before it dies, if you try to excellerate, it hesitates, then dies.  When you get it off the road, all electrical components such as the dash lights, instrument panel guages, radio and power windows operate normally.  BUT, when you try to restart the engine, the starter motor will not engage, just like you have a completely dead battery, not even a "click".  So far, if you wait a short period of time, like 2-3 minutes, it will then start as you would normally expect it to.  It will then run every time there after.  But, then do it all over again when you least expect it.  I took it to the local Chrysler dealer and they checked it out and said there were no problem codes in the computer and everything else looked just as it should. It has a new fuel pump and is maintained very well.  The only repair history this vehicle has concerns the A/C system.

The thing that has me stumped is the fact that the starter motor will not function at all when this happens.  Bad relay?  Bad ignition switch?  What would cause it to just die, then make the starter not work at all.  Then a few minutes later work just like nothing ever happened at all.

Thanks in advance for any advice you may have.
Answer -
Hi Mike,
I am a little limited in answering your question in that I only have the Haynes manual, not the full wiring diagrams. However the starter system is pretty well laid out there.
The battery supplies fuse 5 (40A) in the power distribution center under the hood which then supplies one section of the ignition switch. When the starter position of that section is closed power goes to fuse position 10 (3A) in the junction block (or fuse block) under the dash which then sends the power to the starter relay control coil in the power distribution center which is then controlled as to when to actuate by the powertrain controller (it grounds the other end of the coil). I think the best way to figure this out is to have a voltmeter on board so you can verify whether voltage is getting to each point in that chain when the starter fails to work. You might want to recruit a helper to operate the ignition switch when this happens so you can do the measurements. For now you could check to make sure those two fuses are in good condition (tight in their sockets, examine carefully to verify that there is no subtle crack in the internal conductive wire) and that the starter relay is inserted firmly in its socket. The wire from the first fuse to the ignition switch is red, from the ignition switch to the fuse under the dash is yellow, from the fuse to the relay is yellow/red and arrives at pin 86 of the relay. That relay should click when the igntion is put to the start position. If it doesn't, and there is 12v on 86, then either the relay is bad, or the powertrain controller is refusing to go into action because it doesn't see the trans to be in park or neutral for safety purposes.
Now the problem I have is coupling this with why the engine dies at the same time. It could be the first fuse in the chain or the ignition switch but I don't know what the "run" position of that section also controls (because the diagrams are too incomplete).  But my thinking is that if you can get the reason for the no starter motor you will also get the die off of the engine solved.
'96 marked the first year of the OBD-II system and that may have deprived you of the ability to read the fault codes that might be stored in the controller by using the ignition key. But try turning the key: on-off-on-off-on within a 5 second period. Then watch whether the check engine light begins to flash, pause, flash, pause, etc. Count the number of flashes between pauses and give me count result in order. That may still be available, if not, then only a separate reader can get the store codes.
Roland

Answer
Hi Mike,
Thanks for the positive feedback.
It was good that you found the cause of the dying out. Another user of the allexperts site noticed your question about the starter problem (it was listed in the previously answered question archive) and wrote me to ask if you had solved that also? If you have, please let me know and I'll tell him what you learned.
Roland