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Discussion Starter · #1 ·
repaired some pin sleeves in the middle connector pack at the pcm and thinkng I might have got a few wires mixed. I need to know what color goes to which pin. There are only 10 wires here.
The truck started then stopped. I dont know if a fuse blew or the ASR is engaged and wont let the truck start again.
It seems there is no spark. I would be able to get it to go by finding the wire that wasnt fitting well and make it fit better then the truck would start. Thats why I was told by a dealer serviceman that it seemed like a pin fit issue and I had to bring the sleeves back to the proper gauge. I squeezed them and put them back on.
What would happen if I got two wires in the wrong place in the center connector to the pcm? Would I blow a fuse?
I have been diagnosing this a while. The ASR activates becasue of an arc where the pin sleeves were loose. I think due to bring the car from a hot climate to a cold climate. I found some broken pin sleeves and managed to resolder the sleeves on to a length of wire and got them to fit again. I made them fit back in the harness connector. But today when I was working on the middle connector pack on the pcm 4 pin sleeves were broken and I think I may have switched two wires after repairing them.
What would happen if I switch the two and they are wrong?
Will I blow a fuse? Is there a fuse? Where do the wires in that connector pack go?
I am good at soldering and I think i did that part well. I think I just misplaced a few wires. I only have a haynes manual and I dont know what all the numbers mean on the chematic.
Is there a pin number and the color wire that goes to that pin in the pcm labeled in the manual?

Help please.
 

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repaired some pin sleeves in the middle connector pack at the pcm and thinkng I might have got a few wires mixed. I need to know what color goes to which pin. There are only 10 wires here.
The truck started then stopped. I dont know if a fuse blew or the ASR is engaged and wont let the truck start again.
You say that the truck actually started? Is it a throttle body injection or
sequential port injection? If it is sequential port and you got the pins
wires mixed up, you may have the injectors mixed up. I don't have
the pinout/colour code for a 97 V6 unfortunately. Those are available
in the Haynes or Dodge shop manual for the year and model of your Dakota.

( BTW..on mine, the Middle PCM connector (c2) is a 32 pin connector.

It seems there is no spark. I would be able to get it to go by finding the wire that wasnt fitting well and make it fit better then the truck would start.

Thats why I was told by a dealer serviceman that it seemed like a pin fit issue and I had to bring the sleeves back to the proper gauge. I squeezed them and put them back on.
How do you know for sure it was a pin fit issue at the PCM/ECM?
THERE WILL BE NO SPARK if the ASD relay is operated for some reason.

If the PCM detects a serious condition, it will shut down the coil driver, the injector drivers and the O2 sensor heaters. If the internal coil driver is prevented from
operating by the PCM, the coil will NOT produce a spark.

Sometimes it's just a little corrosion that can be cleaned with distrurbing
the pin configuration in the connector.

If you had to do more than one, you should have made a drawing of
the connector pin layout and tagged the wire(s) that the pin(s) is connected too with a masking tape tag first.

What would happen if I got two wires in the wrong place in the center connector to the pcm? Would I blow a fuse?
Not necessarily. On my 98 5.2 V8, there are 32 pins on the middle connector
(C2), some of those are injector drivers. But there are also transmission sensors and controls on that connector as well.

I have been diagnosing this a while. The ASR activates becasue of an arc where the pin sleeves were loose. I think due to bring the car from a hot climate to a cold climate. I found some broken pin sleeves and managed to resolder the sleeves on to a length of wire and got them to fit again. I made them fit back in the harness connector. But today when I was working on the middle connector pack on the pcm 4 pin sleeves were broken and I think I may have switched two wires after repairing them.
Sounds like you have more issues with that connector than just a couple
of mixedup wires. You really need to get the dodge shop manual for
your truck that has the pinout and colour code used for the year of manufacture. To trouble shoot, not knowing what is what and what the
colour codes are supposed to be for those connector pin functions is like
working in the dark.
You may get lucky, but then again maybe not.:D


What would happen if I switch the two and they are wrong?

If only two were switched and these are not direct shorts, you won't
blow a fuse..but depending on what is at the other end..you COULD
BLOW an internal TRANSISTOR DRIVER inside the pCM, and once that
happens the PCM is rendered USELESS .

Will I blow a fuse? Is there a fuse? Where do the wires in that connector pack go?
As I mentioned, you need to get the wiring diagram for the year and model
of your dakota. All wiring and pinouts are available in the Dakota shop
manual. At this point in time, it may very well be a good investment for
you than hit and miss troubleshooting..because if you connect the wrong
wires to the wrong pins, you could up screwing up the PCM.

I am good at soldering and I think i did that part well. I think I just misplaced a few wires. I only have a haynes manual and I dont know what all the numbers mean on the schematic.
You can't read the wire diagrams or colour charts on the Haynes manual?
What are you doing then, troubleshooting a PCM style of problem? :D

Is there a pin number and the color wire that goes to that pin in the pcm labeled in the manual?
Yes..but the PCM pin functions and wire colour codes are scattered within
the various wiring diagrams.

First of all on page 12-19 on my Haynes manual (98 Dakota) there is an
explanation of the colour code short form used in the wiring diagram and
the circuit functions.

In section 12-24 of the chassis electrical system, you will see the fuses, the ASD relay and it's contact functions:
The contacts go to a joint connector in the PDC which goes off to
other functions for engine control.

If the ASD relay operates, it is detected by the PCM on pin12 of C3.

The injectors are controlled by injector drivers at C2 (middle)
pin 4, (#1) pin 15 (#2), pin 5(#3), pin 16 (#4), pin 6 (#5) pin 12 (#6)
On my Haynes manual there are more injectors shown for V8s and V10s
as the wiring diagrams are taken directly from the Dodge Shop manual
which also covers the V10 engine.

The ignition coil (primary winding) driver on the PCM is C1 (the first connector) pin 7 and ASD relay control is pin 3 of PCM Connector C3.

Yours may be slightly different from mine, but the nomenclature and
symbols should be the same.

On mine there are THREE 32 pin PCM connectors (C1, C2, C3).
Not all 32 pins are used on each connector though.

If yours is a sequential port injected V6, then there should be more
than 10 pins per connector...otherwise it may be the old throttle body ECM?
 

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Discussion Starter · #3 · (Edited)
thanks Carverman, I have read your posts when you help others.
Thanks for helping me today.
I took the manual over to the truck and reconnected 4 wires to their original position.
That is if I am reading the manual right.
I went to an electronics teacher on his lunch to ask where the circuit numbers are located.
It seems to match.
In the haynes manual, if i am correct, the pcm has connectors labeled C1, C2, and C3.
I am dealing with C2 and I was able to find the colors and numbers that correspond.
The only thing is the orange wire at pin 31 which is labeled 5 volts for automatic transmission. I am driving a manual. Still thinking I may have misread the diagram.
Stilll no spark.
is the ASR active or could it be a fuse?
if so which one?
Is there a fusible link?
then or maybe its that i blew the pcm
Is there a way to check if the pcm is functioning without a dealer?
I am afraid I may have fried the pcm with 5 volts.
If its out should I consider getting another kind of PCM offered online for better performance?
Someone suggested I test for power from the pins.
Check resistance with an ohm meter?
Will this let me know if the pcm is bad?
Thanks for your time.
 

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I took the manual over to the truck and reconnected 4 wires to their original position.

In the haynes manual, if i am correct, the pcm has connectors labeled C1, C2, and C3.
Yes. C1 is towards the front and C3 is towards the firewall. They may have
something on the connector identifying which is which, On mine, C2 is a white connector and the other two are black.

I am dealing with C2 and I was able to find the colors and numbers that correspond.
The only thing is the orange wire at pin 31 which is labeled 5 volts for automatic transmission. I am driving a manual. Still thinking I may have misread the diagram.
No, that is correct. The PCM sources +5 volt to the automatic transmission
sensors on pin 31. If you don't have an automatic, then that pin
SHOULD HAVE NO CONNECTION TO THE OUTSIDE WORLD. The manual
transmission has no need of that voltage.

Stilll no spark.
is the ASR active or could it be a fuse?
if so which one?
Well. the ASD relay coil is operated by the PCM on C3 pin 3 .
When the relay contacts close (operated) there is a sensing of those
contacts on pin 12 (C3) which is the ASD relay output.

The closed contacts of the ASD supply power to:
1. ignition coil primary winding
2. the injector coils
3. The oxygen sensor heaters

Inside the PCM there are solid state drivers that pull down the low side
of the ignition coil to ground..that pulses the coil primary at the correct
timing sequence to provide a spark at the appropriate cylinder just before
TDC on the compression stroke. The fuel injector drivers (on C2) will pull
the low side of the fuel injector coils to ground at the appropriate timed
interval during the compression stroke.

The timing for the ignition and fuel injection is derived from the crank sensor
and the cam sensor (inside the distributor).

The ASD relay is fused by a 10a fuse in the PDC.

The ASD power contact is fused by a 30a fuse in the PDC.

When the relay is operated (the power contact) feeds +12v battery
(from the 30a fuse) to the ignition coil primary at coil connector
pin 2.
It also feeds +12 volts to ALL the fuel injectors.
It also feeds +12volts to the 02 sensor heaters.

The low side of the ignition coil primary is controlled actively by an open
collector power transistor inside the PCM at C1 pin 7.

Is there a fusible link?
Yes in the PDC, but it is a 140amp between the battery positive post and
the alternator output. That would be hard to blow with what you were
doing.

then or maybe its that i blew the pcm
If you connected ground or +12volt to the wrong pins on the PCM, yes
you can blow out that pin function.

Is there a way to check if the pcm is functioning without a dealer?
Not really, you can determine if the ASD relay is operated or dropped
out. Take the cover off the ASD and with a digital voltmeter to ground
check the contacts to see if you have +12volt battery on the contacts
and with the relay operated. If the relay has de-energized then the PCM
is either damaged or for some reason deactivated the ASD because it is
detecting some other problem..perhaps on it's connectors?

I am afraid I may have fried the pcm with 5 volts.
Well it is a computer and it runs internally on a regulated +5volts like most
computers
. The battery +12 is regulated to +5volts. Most sensors run on
+5volts for that reason. If you connected a ground to a +5volt source
that appears on a specific pin on C1 and C2, and the +5v supply can't
tolerate a short, you may have fried the +5volt supply in the PCM,
I don't know..you can test for +5v with a digital voltmeter. If it is still
there then the +5v source is still ok.

You should never work on a complex piece like the PCM without a better
understanding of what the connections are and what functions they control.
Now you are learning the hardway...unfortunately. :D

If its out should I consider getting another kind of PCM offered online for better performance?
If you have the money..sure, but what kind of performance do you expect
from 3.9 v6 magnum? Better gas mileage?
Someone suggested I test for power from the pins.
Well that's a start. You have +12volt battery coming on pin 22 of C1..
that is fused at the PDC with a 20amp fuse#1.
+5volts source should be at pin 17 of C1 and at pin 31 of C2.

CHECK ALL THE FUSES IN THE PDC TO MAKE SURE YOU HAVEN'T BLOWN
ANY, LIKE THE FUSED IGNITION/START/RUN function.

Check resistance with an ohm meter?
Will this let me know if the pcm is bad?
Waste of time..what resistance do you know is good and what resistance
is considered bad?
 

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Discussion Starter · #5 ·
thanks
i follow you
Now I should test the asd relay.
Where is the relay located?
and to confirm,
the fuses have clear windows that when blown would turn black or show sign of blowing?
do I have to pull them?

now I am thinking it comes down to blown fuses, relay or pcm.
Anything else?
Gracias
 

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thanks

Now I should test the asd relay.
Where is the relay located?
It is located along with other relays in the PDC (power distribution center).
It is a black box next to the battery on the left fender. Pop the lid off
and on the underside of the lid will be listed the location of the relays and
fuses.

the fuses have clear windows that when blown would turn black or show sign of blowing?
do I have to pull them?
Most of them are the mini style push in. (see the diagram) On the top of the fuse will be the amperage indication.

http://www.wiringproducts.com/conte...r_fuses.html?gclid=CPHMv9aki7ACFWkCQAod_g1Gqg

You have to pull the fuse to examine the fuse element through the side of the fuse. If it is blown, the element will have a gap in the middle. There may be some spare fuses there in the PDC as well. If you find a blown fuse, you can buy an assortment of these at any automotive store.

now I am thinking it comes down to blown fuses, relay or pcm.
Anything else?
Gracias
It can be ANYTHING. Check all the fuses.

Verify whether the ASD relay is operated or not. You can do this by popping off the plastic cover on the relay from the bottom..there are two tabs.

Get a small flat screwdriver and carefully pop off the cover, find the contacts.

There will be a common which is the fused battery.
There will be an NO operate contact that will contact the common (swinging contact) when the relay is operated.
The other contact NC is the non operated contact when the the PCM decides to release the relay because it is not happy about something.
That contact is not connected to anything.


So, if the relay is not operated, then the coil, injectors and 02 sensors will NOT get +12v fused.

Now, since you like poking around there, you can bypass the ASD to see what STILL may be working.

This method is for test purposes only!
I have designed a jumper bypass for mine, in case I had to troubleshoot
a no start problem.

NO = normally open (closes with common contact on relay operation by pCM)
NC = normally closed (relay released by PCM)

The ASD relay has 5 pins on the base. 3 are in a row one way. The outside pins (1 and 2) are the coil. Pin 4 (middle) is the 30 amp fused contact which
also goes to the NC contact.


The normally closed (unoperated)contact is at the farthest edge of the relay base (3) and the one next to it (5) is the Normally open(Normally operated) which should go to the coil and injectors.
__ and | is the pin contact orientation


...........................__ 2 (coil) (from 10amp fuse)
3 .............5
| NC......... | NO ....__4 (common contact) from +30amp fuse

..............................__1 (coil) from pcm control

Take a jumper wire with a couple of flat blades and insert it between
the NC (3) and NO (5) contacts in the relay SOCKET..NOT THE RELAY.
If you don't have any other problems the engine will start and run normally.

I have tested this on my own truck. The check engine light will NOT
come on, so everything should work as if the ASD relay was plugged in and
operated normally by the PCM.

IF your PCM is still working and triggering the coil, you should see a spark at
the coil's high voltage output tower which should get directed to a sparkplug
for testing purposes. Take a spark plug
wire and plug it directly into the coil tower and the other end to a grounded spark
plug against the engine so you can see the spark. Crank the engine with ignition
on.

IF the PCM is still working and no fuses are blown, and both the CRANK and CAM'
sensors are sending signals to the PCM, the PCM should trigger the coil primary
at the proper ignition sequence.
 

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Discussion Starter · #7 ·
yeah i suppose i do like pokin round in there
here is what i got from todays testing
the asd relay coil pin 3 gave me a hot signal to my test light
its all i had today
checking pin 12 at the pin sensing the asd contacts, well,
all I heard was a click in the relay when i touched a grounded test light to the wire for that pin. all the others u said would have voltage do except for the ignition coil at pin 7. I only heard a click when i touched the test light to the wire on that pin as well.
the 5 volt leads just gave me a much dimmer light
tomorrow I will try the asd bypass
thanks
 

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the asd relay coil pin 3 gave me a hot signal to my test light its all i had today
Glad you found it. I suppose you checked the appropriate fuses in the PDC
while you were testing the ASD?

Pin 3 is the normally open contact is connected to the coil and injectors.
Pin 4 (the middle one should have 30amp fused battery on it) it is the
movable relay contact.

checking pin 12 at the pin sensing the asd contacts, well,
all I heard was a click in the relay when i touched a grounded test light to the wire for that pin.
Not sure what a grounded test light will do on pin 12, but the lamp is low resistance, so in essence you are grounding the ASD relay contact sensing
input when it is expecting +12v..so it will do something that it normally
doesn't do...the click you heard may be the relay being released..I don't know.

12v test lights are not the thing to use on computer sensing inputs.
you are better off to use a digital voltmeter there
.

I have designed a test circuit for the ASD relay with just an LED and a
510ohm resister (current limiter for the LED). All I have to do is
connect the Led and resistor to the NO contact (pin 5) to verify if the relay
is operated or not.

It is a good visual indicator when you are troubleshooting.

If you pull the ASD relay and examine the contacts, the two that touching on the de-energized relay is the middle (4) common and the NC (3).

You want to monitor the NO contact (Normally Open) for closure when the ASD relay is operated.

all the others u said would have voltage do except for the ignition coil at pin 7. I only heard a click when i touched the test light to the wire on that pin as well.
Pin 7 is the ignition coil driver on C2. But you shouldn't be using a test light
on these pins. Go out and get a cheap DMM (digital multimeter) and use
that.

That pin is the open collector coil primary driver and it will pull the
low side of the coil primary to ground, creating the emf pulse in the coil
(when the pulse goes away), so that will then cause the emf to collapse in the
coil's saturated core, and cause a counter emf pulse to appear on the coil's
high tension secondary winding.



The coil is an autotransformer. The coil's primary has a battery and ground connection, but the secondary winding that produces the spark pulse is only connected to the coil primary at one place inside the coil.

The other end, the free end of the secondary coil, (where the high voltage is developed) goes to the coil tower.

By grounding out pin 7 on the test light, you are in essense connecting the
collector of the driver to ground through the light and that is NOT the
way it works.


It wants to see a coil winding, one end connected to +12volt battery and it will pull the low side of that coil to ground itself.

That causes current to flow in the primary while the PCM driver on pin 7 grounds the
COIL'S pin 2 (on the 2 pin coil connector on the bottom of the coil).

the 5 volt leads just gave me a much dimmer light
tomorrow I will try the asd bypass
thanks
Well as I mentioned, using a test light on computer voltage circuits is a crude
way of troubleshooting in my opinion. The lamp requires a fair amount of current to light up, and it is too low of a resistance to start with, so it grounds out any
sensitive circuits,

Using a digital voltmeter is a much better way of analyzing the problem.

Get one, set it to 12 volt range (or 20 volt range) and probe away.

The multimeter will give you an exact voltage reading.

At least with the test light glowing dimmer on the +5volt PCM pins, you
can feel better that the PCM is still producing +5Volts.

Carry on, but get the right tool, it will speed up troubleshooting. :D
 

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Discussion Starter · #9 ·
wow, alot to look at.
Thanks again.
I tried the jumper on the asd. nothing.

i took the cover off the asd.
I saw what parts you mentioned but didnt really know what i was looking at.
I am going to study the manual schematics to recheck that all the wires i moved are correct
somethiing is different now though. I dont smell gas
up until the day of the wire misplacement on C2, when it would not start I would smell fuel.
today I did not smell fuel. maybe because the wind was blowing but I did put my nose close to the cover of the air inlet and did not smell gas.
I wish it was quantum physics!
 

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wow, alot to look at.
Thanks again.
I tried the jumper on the asd. nothing.
The ASD bypass will work ONLY if there is nothing else wrong with the ignition
or fuel delivery sequence, ALL the wires to the PCM are in the correct
pins AND the PCM is good.

Otherwise, there is something else wrong that prevents it from starting and running.

i took the cover off the asd.
I saw what parts you mentioned but didnt really know what i was looking at.
That was probably "too much information"..I am familiar with relay parts and
operation, and can even modify a relay to provide active indication of
what is happening, but..then again..I spent over 40 years in the electronics
industry and troubleshooting, so I tend to get maybe more involved than
most people.

I am going to study the manual schematics to recheck that all the wires i moved are correct
That's a good idea. It doesn't take much..one crossed important wire.

somethiing is different now though. I dont smell gas
up until the day of the wire misplacement on C2, when it would not start I would smell fuel.
For you to smell gas, the injectors need to be operated by the PCM.

On a Magnum V6, you will have 6 of them, one for each cylinder.
On C2 the injector drivers are:
#1 pin 4, #2 pin 15, #3 pin 5, #4 pin 16, #5 pin 6, # 6 pin 12

today I did not smell fuel. maybe because the wind was blowing but I did put my nose close to the cover of the air inlet and did not smell gas.
I wish it was quantum physics!
Well if the ASD is not being operated by the PCM, because it may be damaged or doesn't like some important signals coming in (crank/cam sensor), the injectors may not turn on.

Back to basics for you, I guess.

At the bottom of the igniton coil, there is a plug to the primary winding.

Pin 2 is the +12 volts from the ASD relay (if it is being operated by the PCM)
and pin 1 is the PCM coil driver (low side).

You can use your test light probe on pin 2. That is the fused +12volts that
goes to the ignition coil and injectors. If the +12v from the ASD is not there..
THEN:


1. the ASD relay is not being operated, (no ignition and no injector operation)
2. the ASD supply relay fuse is blown
3. You may have a connection problem in joint connector #2 in the PDC
4. you may have a bad or incorrectly connected sensor
5. PCM itself


IF you have +12volts there, then it may be a fuel pump delivery problem
as the PCM operates the low side of fuel pump relay, which also has it's coil +12v fused at the PDC.


However, one step at time now. Check out points 1 & 2 first.
 

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Discussion Starter · #11 ·
ok no voltage to the coil. all wires are correct.
also someone stole the fuel so I put in a gallon and a qaurter, largest amount I could get there today and no spark and no fuel smell. The fuel pump is on constant when the key is in on position. Maybe becasue I am on a hill front facing down and the fuel pump hasnt enough to put in to the injectors.
I have to get more gas to the vehicle and I need spark.
There are only ten wires in connector 2. I did put a wire to the 5 volts pin that shouldnt have been. With only ten wires it seems that i could see , with your help, possibly all potential of what damage I may have caused.
I am thinking that the pcm is damaged. What else could I have damaged?
The connections to the sensors after the C2 connector were fine up until when the whole thing went out. The truck started even with the crossed configuration of wires then quit. All the fuses are good.
May have burned out a sensor?
Thanks Kind Sir! :eek:
 

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ok no voltage to the coil. all wires are correct.
So your checked the plug on the bottom of the coil? +12v from the
ASD relay (if energized) should be at pin 2. You can check that at
least with a 12volt test light. Pin 1 of the same plug is from the PCM
coil control.

In any case, the PCM controls both leads, so if the PCM is suspect
then it would make sense..but first...

also someone stole the fuel so I put in a gallon and a qaurter, largest amount I could get there today and no spark and no fuel smell.
You do seem to have your problems these days. :D
No spark, no injector operation...so no fuel smell, makes sense.

The fuel pump is on constant when the key is in on position. Maybe becasue I am on a hill front facing down and the fuel pump hasnt enough to put in to the injectors.
If the tank is dry, then the pickup screen in the tank may not have enough
to prime the pump..you need about 2 gals in there (that's the reserve),
and it should be on a level surface. The only way you can tell if there is
fuel present in the fuel rail, is to get a fuel pressure guage and put it
on the fuel pressure test port (black cap) on the fuel rail on the driver's
side. If the pump is working, there should be 45psi..but of course if the
pump ran dry..then the pump could have a problem, since it is cooled by
the fuel in the tank.

I have to get more gas to the vehicle and I need spark.
If the fuel rail is pressurized with gas, then you also need to find out
why there is no spark and more than likely the injectors are not working.
The ASD supplies +12 to both the coil and the injectors, so it has to
be operated. When you tried the contact bypass, it didn't work,but
I don't remember if you tested for +12volts at the coil with the bypass.

There are only ten wires in connector 2.
Ok, all 32 pins do not have to be used in each vehicle type. The PCM
is generic to the 4 cylinder, V6, V6 and V10 motors, so depending on
engine configuration, not all pins will have wires on them for C2.

all is needed is 6 wires for injector control, AND pin 10 is the generator field,
that is required on all motors, pin 23 is oil pressure signal and pin 27 is
VSS (vehicle speed sensor) , pin 25 is VSS ground and pin 31 is +5 volts.
If you have a manual transmission, the other pins that are used for the auto
are not wired up, but the signals will still be there on the PCM, even if
not used. So how many wires are needed? ..10, if you don't have the
automatic, the +5v on C2 is not used either.

I did put a wire to the 5 volts pin that shouldnt have been. With only ten wires it seems that i could see , with your help, possibly all potential of what damage I may have caused.
It depends on what wire was erroneously connected to pin 31. The +5volts
is a regulated +5 and more than likely, like most +5v solid state regulators
it will shut down if it detects a short, so that in itself shouldn't be the
cause.

I am thinking that the pcm is damaged. What else could I have damaged?
If you connected only the fuel injector control wires, there shouldn't
be any damage..since the the other side of the fuel injector is normally
at +12v, but again, I don't know what you connected to what.
The connections to the sensors after the C2 connector were fine up until when the whole thing went out. The truck started even with the crossed configuration of wires then quit. All the fuses are good.
May have burned out a sensor?
The only sensors that would apply in your case with C2 (manual tranmission) would be:

a) Transmission Temperature sensor...and that's a thermistor, so it's hard to blow one of those. (not likely) Would the truck start? Yes, but it would set a check
engine light with the P-code indicating that sensor.

b) engine oil pressure..not sure if that would prevent it from starting.but it
would set a check engine code..

c) generator field driver..this is the low side of the generator field that
the pcm controls to provide battery charging regulation. On these daks.
the pcm acts as a voltage regulator..connecting that erroneously would
not prevent it from starting and running..it just wouldn't show a charge
on the voltmeter.

d) output speed sensor ground...don't know what that would blow if
connected to the wrong pin..

e) VSS speed sensor signal (even if this became defective, the truck would
still start and run..but the speedo wouldn't work anymore.


So not knowing what you did, and the fact that it started and ran for a bit,
could be:

1. Fuel pump pressure (but you would still get a spark) as the fuel pump
relay (low side) is controlled by the PCM on C3.
The only way you can verify whether there is gas and at 45psi is
at the fuel rail test port.

2. PCM (If the ASD is NOT operated, the PCM knows this by sensing it
at pin 12 of C3. This would more than likely prevent the spark and injectors
from working as well.

3. Ignition coil driver (C1 pin 7)

4. Crankshaft position signal (C1 pin 8)

5. Camshaft positions sensor (C1 pin 18)

Both of these sensors are fed from +5volts sourced at the PCM (C1)
so you need to check the +5v (C1 pin 17) to make sure that the +5v
is still being sourced to the sensors.

If not, then the PCM is damaged..and you wont get spark or fuel injection
because the PCM can't determine the engine timing.

You need a Digital voltmeter to check this..not a +12volt test lamp!
 

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Discussion Starter · #13 ·
i been trying to post but for some reason, maybe this dial up connection, I have not seen my reply's posted.
ok so I have done the check with the light on the coil pins and I double checked the wires and no spark.
:eek:
 

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i been trying to post but for some reason, maybe this dial up connection, I have not seen my reply's posted.
ok so I have done the check with the light on the coil pins and I double checked the wires and no spark.
:eek:
Ok, let's summarize what we know.

1. You had some initial problem with the PCM connections.

2. You fixed the problem by soldering/tightening some or all of the pin
connections on C2. Any work done to this area should be done with
the battery positive disconnected, and the wires being touched... carefully
identified..yada..yada..

3. The engine started with the wires crossed and ran for a few seconds
then died.

For the engine to start and run, it needs:

1. Ignition coil pulsed by the PCM
2. 12v supplied by the ASD which is controlled by the PCM
3. Injectors connected to C2 on the correct pins to work
4. Fuel pump working and fuel rail pressurized at 45 psi
5. Crank and cam sensors to be working
6. No blown fuses in the PDC affecting engine operation
7. ASD relay energized so that injectors and coil get +12v

At this point, other than fuses (which you have checked to be ok),
and the fuel pump/fuel rail pressure (which is controlled by the
fuel pump relay), which is controlled by the PCM, which you
probably have not checked at the test port on the fuel rail....

leaves the following.... which could be considered faulty at this point in
the troubleshooting:

1. PCM ?
2. Crank sensor?
3. Cam sensor?

and maybe ALL OF THE ABOVE?

The cam sensor is in the distributor, the crank sensor is in the bell housing
on the passenger side.

To check both of these hall effect solid state sensors working off +5volts,
you need an analog voltmeter preferred, (not a digital). There should be 3 wires
going to each sensor, +5volts, ground and signal back to the PCM.

Crank sensor:
You can disconnect the plug going to the crankshaft sensor and check
for power and ground on the harness side. Pin 3 is +5v, pin 2 is ground
and pin 1 is sensor signal. Reconnect the plug to the sensor and using
an analog voltmeter backprobed to pin 1, turn the ignition key and
and either crank the engine or turn the engine with a breaker bar at
the crankshaft pulley. If the power is there, and the sensor is working,
you should get between 0.5volts and 4.5volts FLUCTUATIONS as the notches in the
flywheel/driveplate pass the sensor. You may need to rotate the crankshaft
through at least one revolution to see this.

Cam sensor:
This is a +5volt hall effect solid state sensor. Pin 3 is +5v, pin 2 is ground
and pin 1 is signal. Pull the fuel pump relay and disconnect the coil plug
when checking this for safety's sake.

As in the crank sensor, with the ignition key on verify that +5v is present
on the wire harness to the sensor. Connect the positive lead of a voltmeter
to #1 and the negative lead to #2 and check for +5volts.

As with the crank sensor, the voltmeter should be on pin #1 (signal) with
the key on and the engine cranking. You should see fluctations between
0.5volts and 4.5volts with the engine cranking.

IF NO +5VOLTS IS AVAILABLE AT EITHER SENSOR, Find ANOTHER pcm
AND REPLACE THE ONE IN YOUR TRUCK.
The existing PCM no longer
is supplying +5v to either sensor.

IF no pulse detected at either sensor with ignition key on and engine
either cranked or turned by hand with a breaker bar.
..REPLACE THE
DEFECTIVE SENSOR (OR SENSORS).

That's about it as far as troubleshooting it further.
 

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Discussion Starter · #17 ·
i got 5 volts to the sensors does that mean the pcm is okay?
need to get someone to turn it over for me still to check for the pulse
i guess nobody stole my gas
i think that my gas gauge doesnt work now.
I pulled the relay and there is no noise at the fuel pump it stopped
I put in 5 gallons of gas sand rolled the truck level but the pump was still pumping.
I saw no leak and smelled no gas.
I wonder if I got something shorted in the fuel pump relay?
would that make no spark sent?
OH i CHECKED THE PIN THAT GOES TO THE COIL.
i HAD SOMEONE TURN THE KEY THEN AND IT SEEMED THAT i WAS GETTING .22 volts
I will get my friend out there again and check it again and the pulse as well.
 

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Discussion Starter · #18 ·
ok I checked the sensors
got 5 volts pulsing from the crankshaft and miuch less than that on the camshaft sensor like .5 to 1 volt
next with the jumper over the asd relay i got 11.96 volts at the coil
check ya in about 10 hours!
I wonder what time schedule you are on.
Its 10:30 pm in california
thanks
 

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ok I checked the sensors
got 5 volts pulsing from the crankshaft and miuch less than that on the camshaft sensor like .5 to 1 volt
next with the jumper over the asd relay i got 11.96 volts at the coil
check ya in about 10 hours!
I wonder what time schedule you are on.
Its 10:30 pm in california
thanks
I'm in Ottawa on EST..that is about 2 hrs behind you..so when it's 10:30pm
in Cali, its 12:30am here. I may or may not be on the computer at that
time.

The cam sensor (if the +5V is there on pin 3 of it's plug), should give you between
0.5volts and 4.5volts when pulsing MEASURED on pin 1 OF IT'S 3 PIN CONNECTOR.

Less than that, the sensor is considered to be DEFECTIVE.
This is a common failure on the Dakotas and can happen at anytime
because the sensor is a solid state hall effect transistor which senses
a magnetic ring inside rotated by the distributor shaft...each pulse is timed
so many degrees before TDC and the sensor is basically a pickup coil similar
to the old points system and the 6 or 8 lobed camshaft that opened and
closed the points to create the spark in the coil.

Now the PCM does that..but it needs good signals from both the cam and
crank sensors to do that.

Sometimes the sensor does not fail completely to set the
P-codes but the PCM can't use a signal that is that weak.

REPLACE THE CAM SENSOR.

INFO
=====================================================
If the SS sensor inside the distributor is not getting the full +5volts
then it won't work and provide the PCM with spark/injector timing
information..so with a dead camshaft sensor..it will NOT start even
if you have +12volts at the coil BECAUSE the PCM controls the low
side (ground side) of the coil to pulse the coil for spark.

The camshaft sensor ground is C1 pin 4.
The camshaft sensor signal is C1 pin 18.
The +5volt supply to both the cam and crank sensors is C1 pin 17.

It's a direct wire connection to the crank/cam sensor for signal to the
PCM.
 
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