Chrysler Repair: 1992 Fifth Avenue wont start: anti-theft system wont disarm?, spark coil, reply button


Question
QUESTION: Hi Roland,

I didn't get a reply button so I had to create a new question.  I will post your last reply below and then do my best to address it.
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Hi Andy,
Let us make sure we are on the same page. The theft security module has a 21-page connector and that is the one that should not be unplugged unless the engine is running. The keyless entry module has 2 8-pin plugs, and if you have a lamp outage module that has 14 pins. All are mounted on the same bracket. So which one(s) were unplugged when you gained access and did you plug which back in?
The pump is supposed to run for about 1 second when you turn the key to run. That is normal. It is supposed to start running again when you move the key to start and continue to do so as long as you are cranking it over. Then it will cut off after you return the key to run position unless the engine is running. The key fob and its module have nothing to do with the engine running or not.
As some point in the past everything worked, correct? What is the history after that?
The check engine light will come on when you first turn the key to run which is to show you that it works. It goes out soon after that, just like the fuel pump does and it doesn't come on again until the engine controller gets a fault code or the engine dies while running.
So keep all that in mind why you are trying various things.
You can temporarily by-pass the ASD relay by jumping from the rear pin to the front pin of its socket. That will turn on the fuel pump. But don't leave it that way because of safety issues related to driving the car with the ASD by-passed and of course the battery will run down. This temporary by-pass will energize the fuel pump and the injectors and the spark coil and test whether the engine no start is related to those items or not.
Please rate my answers, which you can do for each answer if you choose as well as to 'nominate;.
Thanks,
Roland
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OK, as far as the RKE goes, when I gained access the 21 pin plug was disconnected.  I plugged it in not knowing what I was doing and the four way flashers came on.  I grounded the program pin and got the fob to work, though it has a very limited range when it is working.  Also, every time the battery is disconnected, the RKE loses its memory of the fob and the flashers start again.  I'm guessing this is why it was disabled.  Unfortunately, I unplugged it again without the car running, as it won't run.

I am aware of the run cycle for the check engine light.  What is happening is when you turn the key on, the pump will sometimes come on and sometimes not (not at all since I connected and disconnected that 21 pin plug).  When the pump comes on, the light comes on with it.  When the pump does not come on, the light does not either.  I hope I am giving good information here.  Thanks again Roland, it blows my mind that people actually do this for free!-----Andy

ANSWER: Hi Andy,
The 21 pin plug goes into the theft module, not the RKE module. Let us set aside the RKE as an issue in the no start. The theft module is a factor, but it will allow the engine to start, but then it shut down in a second or so if it is not disarmed. What does the theft system warning light on the dash show, if there is one there.
If the fuel pump doesn't hum reliably for a second or so when you first turn the key to run then either the ignition switch is flakey, or the fuse(s) that power the fuel pump are flakey,
or the fuel pump is flakey. Try jumping the pins in the ASD socket to see if the fuel pump is relialble, and also check the output of the ignition switch at fuses 6,7,8 of the fuse box in the cabin.
Roland

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QUESTION: Hi Roland,

    Thanks so much for your patience.  I jumped the ASD with no response.  When I jumped the fuel pump relay itself the pump came on and ran until i pulled the jumper.  With the key on, fuses 6, 7, and 8 are all +12 to ground on both sides.  I plugged the 21 pin connector back into the antitheft module and the flashers did eventually stop, although I was unable to get the fob working.  At this point the Check Engine light and the fuel pump are not coming on at all.  Where do we go from here?-------Andy

ANSWER: Both the ASD relay and the fuel pump relay are actuated by the powertrain control module (pcm) at pin 51 where you will find a dark blue/yellow wire. The pcm should ground that wire for about a second which is what then causes the fuel pump to run for a second. The dark blue/ yellow wire goes from the pcm goes the the 6-pin diagnostic connector in front of the left shock tower and goes on from there to the two relays' actuation coils. So find that dark blue/yellow wire at the diagnostic connector. Then measure its resistance to ground with the key off, then with the key on. It should drop from something or infinite resistance to ground with the key off, and then when you turn the key to 'run' it should show zero resistance to ground for a second or so and you should hear the fuel pump run for a second IF everything in that chain of action is connected and functioning. The other end of the relays' actuation coil is connected to the 12v output of the ingnition switch which you verified to be there by looking at fuses 6-8.
Roland

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QUESTION: Hello Again Sir,

     and thank you for your consistently prompt replies and consistently fresh dignostic ideas.  It's starting to make me think I might not be entirely stupid myself.  I located the diagnostic connector with two blue/yellow wires running to one of its pins, as you had indicated.  It reads 49.5 ohms to ground with the key off and wide open with the key on.  What do you make of this? and Thank You so much for offering what many would demand a lot of money for, for free to people like me.  After a 2012 filled with breakdowns and wrecks, I really need this thing to run.  Thanks Roland!!--------Andy

Answer
With the key off a reading of 49 ohms to ground might by alright, but the question is during the first second or so when you turned the key to run did it drop to 0 ohms, and then did it go to infinite ohms. During the second or so after turning the key to run it should have dropped to 0 ohms and then bounced up high and you should have heard the pump run for about a second. Were you watching and listening when you turned the key to run?

"Wide open" if by that you mean off scale high, then that is the reverse of what it should be as far as to briefly activate the coils of the relays this would have to be grounded.

I am beginning to think that when you disconnected the 21-pin plug that you put the theft system into a no start condition. The question is how to get out of it.
There is a theft system light immediately to the left of the steering column. What is its status?
There is a set of self-tests you can do: cycle the ignition switch to the accessory position 3 times and leave it there. The park and tail lamps should start flashing and the horn should sound twice. Let me know if it does that. Then we can go on with the rest of the tests.
We will try going through the self-test procedure to see if we can clear the no start condition that way.
If not, then the system may have to be 'cleared' by a dealer using the DRB II diagnostic readout box. Lets hope the self test will clear it.
Roland