97 Caravan quits & won't re-start

I have a 97 Dodge Caravan with a 3.0 litre engine and about 180,000
kilometres on it.



Twice in the past few days while driving in stop-and-go traffic it has
suddenly quit. There was no warning like sputtering. It quit suddenly,
just like someone had turned off a switch.



The problem is, it would not start right away. There was no indication that
the starter relay was even activating. It seemed like there was no ignition
or starter power. All of the other electronics seemed to continue working
fine, windshield wipers, four-way flashers interior lights etc were all
fine.



Both times, after about a five-minute wait it started and ran normally.



Both times it happened I did not think to check for a fault code. I tried
it today and the codes were 12 and 55. I dismissed the 12 until I realized
that the battery had been changed about six weeks ago and the van has been
driven a lot since. I would have thought that there would have been at
least 50 starts to clear the 12 code. 55 is the end of sequence code.



Does this sound familiar to anyone? All thoughts are welcome.

 

Now look, you said all thoughts are welcome, so ...

1 Oxygen sensor might affect stalling out. Happens to me rarely but
will happen three, four times in a row then boom, nothing for a month
or three. Sensor is slowing grieving and going south. But took a while
for the "21" error code to show up, quite a few months but it did show
up eventually. And I have the same engine as you do and this is a
"known" problem, stalling out. The sensor runs about $50 for the
equivalent OE part. I have yet to find it though on the exhaust
manifold since only one sensor and it's probably below the air cleaner
and have other things to fix first, like a wheel bearing.

1a Some suggestions here from Daniel Stern and the rest of the crew.
Clean throttle body with Berryman's B12. Clean the AIS motor but I
think you need to take the throttle body off the car to get to the
Automatic Idle Speed motor.

I have been reluctant to do this since I hate to break something while
repairing something and looking at the cables and stuff connected... do
I just squirt the Berryman's or do I take it off and do a proper job
and what about the O2 sensor which is probably more important with gas
being so expensive and now the mixture is probably stuck at rich and
slowly burning up the catalytic convertor which would be megabucks.



2 There are more esoteric problems but it does not sound like the
neutral switch. Would a computer hookup tell you something more?

 

Oops, reading your post more closely, I am thinking of the neutral
safety switch which prevents the car from starting in gear. When it
goes bad, the car won't start. What else would competely prevent the
electric current from getting to the starter?

 

Hi. Thanks for your suggestion. I will have a look at that circuit.

I'm thinking it could also ivolve the Automatic Shutdown Relay circuit.
This is the circuit that prevents the starter from being engaged if the
engine is already running. There are sensors feeding this function but I'm
not entirely sure which ones they are.

 

I do not believe that your interpretation of the functionality of the ASD
relay in the body below is correct.

Bob

ASD shuts down the fuel pump in the event of an accident or if the vehcile
fails to start after some pre-determined interval during cranking. If you
turn the ignition key t ostart while the engine is running I believe it will
indeed enage the starter and youwill hear a nasty greinding of the flywheel
to the starter gear. I'm sure others will correct me since I've never tried
it myself.

 

Okay, thank you. I've been going through the Chrysler shop manual and it
appears as though we're both right (or wrong depending on your viewpoint).

There is definitely a "Double Start Override" that prevents the starter from
engaging when the engine is running but it's just not a function of the
Automatic Shutdown Relay. It is controlled through the Powertrain Control
Module.

I expect that a sensor that feeds the PCM has an intermittent malfunction of
some sort. I just have to narrow it down to which one.

Thanks again.