Dakota Forumz banner

1997 Dakota 3.9 5 speed No spark or fuel pump power

1150 Views 71 Replies 2 Participants Last post by  immattj
I have replaced pcm, crank sensor, relays and fuses, checked wires for dmage, even went as far as replacing coil wires. No spark and no power to fuel pump. Also, fuse 9 on in the panel on driver side of dash has no power as well. Hooked up a jumperwire to fuse 9 and my guages come back. Im not smart in this department. Mechanicalis more me. Help?
61 - 72 of 72 Posts
I believe i found the issue. After running the test you told me to, i kept the multimeter neg connected, and traced the positive cable where its slightly exposed on the pdc to the nut and bolt that hold it down and the volts and ohms fluctuated from 12.54 to 1.23 and stayed in between. Bad connection seems to be the issue
Okay, well, if I am understanding you correctly, that's too bad, because if there was something wrong with that cable or the connecting terminals on the cable & the continuity was intermittent from your battery + post to the stud in PDC where the cable connects, that would probably raise all sorts of holy hell with your electrical system & could certainly account for issues.

So if I've got you correctly, from the - post of battery to the + stud in the PDC you are now reading battery voltage. Checking from battery + to PDC + with for continuity should actually give you a low resistance reading (remember, mine was 0.7 ohms), but since you are now reading battery voltage from - to the + stud in the PDC, it goes without checking that you do have continuity.

Which doesn't solve anything, except that you should have power to your PDC.

Out of curiosity & to review past history, how did you make out on the other checks I previously recommended? Did you ever change your cam position sensor (also known as the distributor pickup coil)?
See less See more
Okay, well, if I am understanding you correctly, that's too bad, because if there was something wrong with that cable or the connecting terminals on the cable & the continuity was intermittent from your battery + post to the stud in PDC where the cable connects, that would probably raise all sorts of holy hell with your electrical system & could certainly account for issues.

So if I've got you correctly, from the - post of battery to the + stud in the PDC you are now reading battery voltage. Checking from battery + to PDC + with for continuity should actually give you a low resistance reading (remember, mine was 0.7 ohms), but since you are now reading battery voltage from - to the + stud in the PDC, it goes without checking that you do have continuity.

Which doesn't solve anything, except that you should have power to your PDC.

Out of curiosity & to review past history, how did you make out on the other checks I previously recommended? Did you ever change your cam position sensor (also known as the distributor pickup coil)?
Not good
Can you expound on that?
Are you meaning that you did check for output directly from the coil & got none
and
that you did check for a flashing test light (meaning trigger signal from PCM) at the black/gray wire to coil & got none?

And as far as replacing the cam position sensor?
and traced the positive cable where its slightly exposed on the pdc to the nut and bolt that hold it down and the volts and ohms fluctuated from 12.54 to 1.23 and stayed in between. Bad connection seems to be the issue
. . . & by that, I assume you mean a bad connection from the lead of your meter to the + terminal stud on the PDC? Because if you mean a bad connection from the + cable AT the PDC, that's a whole different thing. . . .
So, pcm isnt getting power. Found that the wires for the obd connector have been stretched due to being smacked by the clutch pedal and my foot. Now im in deep. And the guy who discovered this issue has now ghosted me......i cant do much more now
So, pcm isnt getting power. Found that the wires for the obd connector have been stretched due to being smacked by the clutch pedal and my foot. Now im in deep. And the guy who discovered this issue has now ghosted me......i cant do much more now

I'm up late trying to order parts for one of my rust buckets that is broken.
What a coincidence!
I live for moments like these!

Okay, I do not think that your OBD port has to be connected in order for your PCM to be powered.
I will not say that I know this to be an absolute fact, but I do recall a member posting about a Dakota with problems & she said she was not getting a CEL because her OBD port was disconnected.

If I am interpreting the schematic in the '97 through '99 Dakota Haynes correctly, it appears to me as if the PCM gets power through 20A fuse #1 in the PDC & goes to the PCM via a red/white wire & if my previous assumptions in a previous reply were correct it would be the C1 plug & pin #22.

And remember that I did preface this with the caveat: IF I am interpreting the schematic correctly.
My electrical whiz tried to jump power to that exact pin wire. He also moved the obd harness as well and we both noticed as he did that, there were clicks
My electrical whiz tried to jump power to that exact pin wire. He also moved the obd harness as well and we both noticed as he did that, there were clicks
Clicks could mean several things. But I still do not think the OBD port would effect the PCM being powered. However, I could be wrong. I often am.
I honestly dont know. Im just about to my breaking point. I have no clue wha to do from here. If i could just hook the coil to an independent circuit/toggle switch, plus the fuel pump, i believe it would run
I honestly dont know. Im just about to my breaking point. I have no clue wha to do from here. If i could just hook the coil to an independent circuit/toggle switch, plus the fuel pump, i believe it would run
You'd have to go back a few yers for that.


Have you performed any of those checks I suggested & if so which ones did you try?
You'd have to go back a few yers for that.


Have you performed any of those checks I suggested & if so which ones did you try?
I havent tested the cam sensor
I havent tested the cam sensor
This


is the cam position sensor (cmp) and on your year & engine Rock is calling it the distributor pickup coil, but same thing. It resides under the distributor cap.

A quick review of some key points I have previously attempted to make:

the PCM provides both the cam & crank position sensors (cmp & ckp) (as well as other sensors) with 5 volts for them to function

the PCM MUST get a signal from both the cmp & ckp or it will not send a trigger signal to the coil from the coil driver circuit of the PCM.

(If you go back through some of the earlier posts to this thread you will find the PDF from the '97 through '99 Dakota Haynes of a schematic showing the relationship of the cmp & ckp to the PCM.)

If the coil is not getting a trigger signal from the coil driver circuit of the PCM it will not operate.

Meaning that if it was me, first I would verify for certain that the coil is not producing voltage to the distributor cap. If it is producing voltage, then the problem is between the coil & the sparkplugs & you can forget about everything I previously typed.

If the coil is NOT producing voltage, if it was me, I would then

verify that the coil was good
if good I would verify that the coil was recieving voltage from the battery for the first 2 or 3 seconds after turning the key to on at the green/orange wire at the coil
(IMPORTANT TO NOTE THAT YOU WILL ONLY READ VOLTAGE FOR 2 OR 3 SECONDS AFTER TURNING THE KEY TO ON & THEN IF NO SIGNALS FROM CKP OR CMP ASD RELAY WILL DE-ENERGIZE AND YOU WILL LOSE THAT VOLTAGE AT COIL AND THIS IS NORMAL)
if I wasn't getting battery voltage for the first 2 or 3 seconds after turning the key to on I would then check the ASD relay by swapping it with a known good one in the PDC

if I did have battery voltage at the green/orange wire at the coil I would then use a LED test light & check at the black/gray wire going to the coil for a trigger signal while cranking the engine--flashing would mean a trigger signal.

If the test light did not flash, meaning no trigger signal to the coil, the Haynes that I am quoting from says to perform checks on both the ckp & cmp & on their circuits, which, I suppose would mean to use the ohm meter function of your meter & check for continuity between the ckp & cmp connectors & their corresponding pins (which are identified on that schematic I previously alluded to) at the PCM AFTER FIRST DISCONNECTING THE BATTERY SO AS NOT TO DAMAGE THE PCM.

But if it was me, I'd probably go to Rockauto & throw a new cmp & ckp at it instead of testing them. If that didn't work, then it would be time to look at the circuits as I described above. Although, when it was me, I did not do that: I skipped ahead to the step that said suspect the PCM so I sent it to a facility that diagnosed & repaired it. I did NOT buy a reman.

What I would NOT do would be to be running jumpers every which way, especially not to the PCM, as I think it is possible that if the PCM is not already f'ed, that might be what does f it.

I am not going back to review all the posts on this, but I seem to remember you saying that one of the things you had jumped was the fuel pump & that it did power up when you did that, but not when you turned the key on.
To further review, I'll remind you of a post I made earlier about the PCM de-energizing the fuel pump relay if it was not getting a signal from the ckp & cmp.

You also mentioned something about your gauges not operating & I seem to remember asking you more about that, but I don't think you ever answered.

At this point, if you go back to the top of this reply I am just finishing up, of the steps that I said that I would have done, which of them have you actually done?

Then we can go from there.
See less See more
61 - 72 of 72 Posts
Top