Engine dies suddenly, speedometer drops to zero while moving

Tiny
JUNKYMAGI
  • MEMBER
  • DODGE DAKOTA
Driving down the road, doesn't matter how long I've been driving, seems perfectly random, engine suddenly dies, speedometer drops to zero, indicating an electrical problem but I don't have a clue where to start.

Putting truck in neutral and turning ignition off (but not to lock) for ~15 seconds then it will start right back up like nothing happened.

It's been getting worse, 30 mile trip a week ago, only died once. On the way back, 3 times, today, 3 mile trip, died 5 times.

1995 Dodge Dakota, v6, 109k miles
Anyone have an idea?
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Saturday, May 26th, 2007 AT 2:55 AM

19 Replies

Tiny
RASMATAZ
  • MEMBER
[quote="junkymagi"]Driving down the road, doesn't matter how long I've been driving, seems perfectly random, engine suddenly dies, speedometer drops to zero, indicating an electrical problem but I don't have a clue where to start.

Putting truck in neutral and turning ignition off (but not to lock) for 15 seconds then it will start right back up like nothing happened.

It's been getting worse, 30 mile trip a week ago, only died once. On the way back, 3 times, today, 3 mile trip, died 5 times.

1995 Dodge Dakota, v6, 109k miles

When it dies, immediately look for spark-No spark continue to check the ignition system till you get it and then comeback
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Saturday, May 26th, 2007 AT 4:45 AM
Tiny
JUNKYMAGI
  • MEMBER
When it dies, the ignition system is completely dead. It doesn't come back by itself. I have to turn the ignition off for a while (while something cools down/resets?) Then when I turn the key back to the on position, the speedometer will start to register my speed again (I'm coasting, when it dies, speedometer drops to zero) then I can start the engine again.

What should I be checking for a spark?
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Saturday, May 26th, 2007 AT 5:05 AM
Tiny
RASMATAZ
  • MEMBER
Disconnect a plug wire, ground it-crank it over-do you have spark?

Try checking the crankshaft position sensor and the ASD relay.
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Saturday, May 26th, 2007 AT 2:34 PM
Tiny
JUNKYMAGI
  • MEMBER
No spark

ESD relay? Need a location for that since I don't recognize the acronym
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Saturday, May 26th, 2007 AT 4:50 PM
Tiny
RASMATAZ
  • MEMBER
Dunno where the ASD relay (Automatic Shutdown Relay) location this relay powers the Injetors/Coil/Fuel Pump-its probably in the power distribution box-

If the PCM don't get a signal from the Cam or Crank sensors. The PCM will turn ground off and de-energize the ASD relay.

Hope this helps-Good Luck
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Saturday, May 26th, 2007 AT 7:22 PM
Tiny
JUNKYMAGI
  • MEMBER
Would the ASD also shut off power to the speedometer?
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Sunday, May 27th, 2007 AT 12:37 AM
Tiny
RASMATAZ
  • MEMBER
I don't think so.
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Sunday, May 27th, 2007 AT 2:17 AM
Tiny
JUNKYMAGI
  • MEMBER
Crud, means it's something closer to the ignition switch, if not the switch itself.

Does the computer control power to the speedometer or does the speedometer's pickup go through the computer?

I'm trying to find what the ignition and speedometer have in common, which is most likely the part that has failed.

Also, went to autozone and found out how to check stored codes and I get 55, which means that's the end of the codes, no error codes are stored :o(
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Monday, May 28th, 2007 AT 12:54 AM
Tiny
RASMATAZ
  • MEMBER
Do you have spark?The ignition has nothing to with the vehicle speed sensor-you need to do some detective work on the ignition and fuel system-The ASD relay plays a major role in the ignition and fuel system. You need to test this relay then go from there.

BTW the PCM activates this relay and in turn powers up the coil, f/pump/injectors.
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Monday, May 28th, 2007 AT 1:53 AM
Tiny
JUNKYMAGI
  • MEMBER
The engine dies at the exact same moment that the speedometer drops to zero. It's happening after only a few seconds of running now, can't drive it any more.

After turning the key off for a few seconds and back on, the speedometer will start to register my current speed again, something electrical has reset.

If the PCM also controls power to some part of the speedometer system, then that's the problem.

If it has nothing to do with the speedometer, then it can't be the problem.

Edit:
I've gone to www.alldatadiy.com and have been looking at wiring diagrams and such. Since the guy at Autozone said it sounded like I had a dying ground wire, I'm going to check the ground for the PCM and hope it's just corroded or something.

Diagrams refer to Z12 as supplying ground for the PCM, if it loses ground the vehicle will not run, doesn't mention whether or not that will kill the signal or power to the speedometer though...

Look to bottom left of the image, G201 is a ground connection, when I get to the truck I'll check that. I'm at work now.


http://www.2carpros.com/forum/automotive_pictures/75980_42396341_1.jpg

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Monday, May 28th, 2007 AT 1:59 AM
Tiny
RASMATAZ
  • MEMBER
If the PCM also controls power to some part of the speedometer system, then that's the problem.

The VSS sent the vehicle speed to the PCM at which time it uses it to control the up shifts, overdrive, and lock-up by using these sensors inputs-ECT, TPS, VSS and brake switch to cancel converter lock-up.

Could be a PCM and grounding problem-If G-201 is the main ground for the PCM it will kill the entire engine management system.

Do you have any shifting problems?

Posted:
Sat May 26, 2007 1:50 pm
junkymagi, New to the forum
Give Feedback | Votes: 0

.
No spark

ESD relay? Need a location for that since I don't recognize the acronym. ASD relay- Automatic Shut Down relay.

Are you getting spark? When it dies out? I need to know this-before we continue

Also do you have any diagnostic trouble code/s?
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Monday, May 28th, 2007 AT 7:50 AM
Tiny
JUNKYMAGI
  • MEMBER
*sigh*
When I got back to the truck this morning, I opened the hood and checked the grounds on the PCM, seemed secure, wiggled the PCM's main plug and it seemed secure.

Started it up and drove it home, no problems. Turned it off while thanking coworker for escorting me home. Went to restart it and it works perfectly now. 30 minutes of idling it up and down, putting it in gear for 20 minutes with the emergency brake on, gasing it once in a while, no dying at all.

GAHH, when I want it to mess up so I can test stuff, it works perfectly, when I need it to work (like going to work) it dies.

I'll post again the next time it screws up, even though I'm paranoid to go anywhere now :/
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Monday, May 28th, 2007 AT 9:00 AM
Tiny
RASMATAZ
  • MEMBER
Do you have an anti theft device or remote start.
You probabaly have a loose power/ground conn. Somewhere which supplys entire system. I would start at the body ground. Move to underhood fuseblock power supply from batt. You can run it all day in the driveway. But hit some bumps. Out it goes
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Monday, May 28th, 2007 AT 3:43 PM
Tiny
JUNKYMAGI
  • MEMBER
The entire system doesn't go dead, radio, heater/a-c fan still blows, windows all of them work.

The only thing that I can see that goes dead is the ignition and the speedotmeter, maybe the tach, but since the engine stops, it's going to read zero if it's working or not.

I've uploaded 4 images to my website which detail the wiring I think may be involved. I'm thinking that there is more than one wire that gets powered when the ignition is switched to ON. One goes to ignition system/gauges and other for accessories. Maybe one going to ignition system has intermittent loce of connection?

I'm going to keep trying to make it die while at the house so I can climb under the dash and see if one of the wires that's supposed to be hot isn't.
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Monday, May 28th, 2007 AT 11:50 PM
Tiny
JUNKYMAGI
  • MEMBER
Well, this is interesting. I drove for 15 miles, several turns, 5 or 6 railroad track crossings, didn't die once. Makes me think it's not a loose connection and an actual part that's partially failed.

After I got home, I thought maybe the ASD relay was going bad. I decided, since they all have the same number and appear to be identical, to switch the ASD and a/c clutch relays.

When I pulled the ASD, it's plastic case was very hot to the touch. Maybe it's overheating causing a failure. When it dies, it's hot and can't cool down because the ignition key is still in the RUN position.

After turning off the key for 15 seconds, it's got a chance to cool off and start working again?

I went ahead and switched the relays between the ASD and a/c clutch. I'll post back if it dies again, will mean it's on either side of it and not the relay itself.

I checked all the grounds for the relay box and PCM, all are tight and in good condition.

Really hope it's this simple, can't afford to have it in the shop for several days/hundreds of dollars chasing down an elusive problem like this.

Edit: well, went to autozone, 4 miles, no dying.
Went up to friend's, 6 miles, died 3 times.
Way home from friend's, 5 miles, no dying.

Soo, intermittent, can't figure it out.

Oh yeah, guy at autozone said it was a loose wire on the ammeter 0-o which can't be possible because it registers correctly during the little "deaths" :(
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Tuesday, May 29th, 2007 AT 7:38 AM
Tiny
JUNKYMAGI
  • MEMBER
*sighs*
Drove 20 mile to Dodge dealer, didn't die once. After I explained the problem they looked at it. 1.5 hours later they came back and said there was something in the intake manafold that needed replaced because it's not getting enough air or getting too much air.

I told them to go back and look again, the speedometer dying at the same instant engine dies (with no warning) means it's electrical.

Another 1.5 hours and they think it's the sending unit on the transmission for the speedometer. They drove it for almost 20 miles in several trips, never died for them :/

I paid for a new sending unit and labor and had them unhook the sending unit to see if it ever dies again (they had to order the sending unit).
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Wednesday, May 30th, 2007 AT 2:44 PM
Tiny
JUNKYMAGI
  • MEMBER
Got it fixed (I think). The speedometer sensor was apparently shorting out the 5v that's running through it, causing the PCM to shut down the ignition system.

Dodge place replaced the sensor and I drove it home and to work a couple times, hasn't died yet.
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Saturday, June 2nd, 2007 AT 6:08 AM
Tiny
95 GREEN DAKOTA
  • MEMBER
I'm on my second 95 Dakota and I have had many issues with bad wire. I found one bad wire under the fuse box under the hood. I found lots of bad grounds. I found bad wires at the fuel pump. At this point I lost count. You might get lucky with a flash light, just looking for bad or corroded wires under the hood near the distributor.
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Monday, February 27th, 2017 AT 3:58 PM
Tiny
KEN
  • ADMIN
Hey,

Great addition to this thread! Please feel free to help out on the site whenever it can add information that will help people.

Best, Ken
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Thursday, March 2nd, 2017 AT 10:14 AM

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