No Bus Error

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,709 POSTS
There is a good chance that when you were moving wires and disconnecting and reconnecting them, you fixed a bad connection. If it starts up again, let me know. We'll figure it out one way or another.

Joe
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Wednesday, June 26th, 2019 AT 12:03 PM (Merged)
Tiny
SLAMMINRT
  • MEMBER
  • 1 POST
  • 1999 DODGE DAKOTA
  • V8
  • 2WD
  • AUTOMATIC
  • 103,000 MILES
I have a 99 Dodge Dakota R T that we had just replaced the transmission in after sitting for about a year and a half in the garage. We started the truck to get the transmission fluid up to temp to top it off, it ran for about 20 minutes at idle when the truck just stopped. Upon trying to restart the engine would turn but not start. The odometer blinks 4 times then shows a No buS message. I tried the key on, off, on, off, on and got a 920 and 921 error. Oh and after the No buS message the check engine light comes on followed by the ABS and gas light, then the security light comes on. I don't know why it just stopped while it was idling. Am I gonna have to get a new computer? Any help would be great. Thanks
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Wednesday, June 26th, 2019 AT 12:03 PM (Merged)
Tiny
JACOBANDNICKOLAS
  • MECHANIC
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The no bus signal identifies there is a break down between the computer and the components. Check to make sure while working on it you didn't loosten any of the wiring going to the PCM. If all is good, you will need to have the PCM tested.
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Wednesday, June 26th, 2019 AT 12:03 PM (Merged)
Tiny
HELENJAY
  • MEMBER
  • 10 POSTS
Good day joe. I thought I fixed it too. I let it run for bout half an hour in the drive way yesterday, then it just shut off. Bit it restarted right away.I didnt even turn key off. So now I think maybe fuel pump over heating? Something is getting to hot and shutting it down? I have 6 relays that are smokin hot while the others are cold?

I really appriciate your help

thanks jason
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Wednesday, June 26th, 2019 AT 12:03 PM (Merged)
Tiny
CH112063
  • MECHANIC
  • 1,320 POSTS
The PCM, or engine computer is like any device that provides power fused. There are two places where all these must be checked with a test light. Under the hood and in the interior fuse block also. You know where the engine compartment fuses are, near the battery in the power dristribution center. Check em with the key on. The crank sensor gets a power feed from the PCM so if a wire was pinched and as it ran wore through you may have lost any one of 3 or 4 fuses it needs. And the crankshaft sensor itself is a tought nut to get to and easy to get damaged or if it's gray wire gets shorted you may have blew the PCM, the controlling computer for spark, timing, and fuel. Check the fuses and make sure the gray wire has voltage while cranking. Ok, I just wanna help. You may have squeexed a wire. Happens all the time, it's not an easy job to change the trans on a truck. Good luck. Ok
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Wednesday, June 26th, 2019 AT 12:03 PM (Merged)
Tiny
JACOBANDNICKOLAS
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Which relays are hot?
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Wednesday, June 26th, 2019 AT 12:03 PM (Merged)
Tiny
HELENJAY
  • MEMBER
  • 10 POSTS
Ok its the 6 on the left of relay box.
Auto shut down
a/c clutch
trailer relay
fuel pump relay
headlamp relay
trans relay

then there are 2 missing under them
thet are suppose to be o2 sensors front and rear
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Wednesday, June 26th, 2019 AT 12:03 PM (Merged)
Tiny
JACOBANDNICKOLAS
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Try replacing the fuel pump relay to see if that takes care of the problem.
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Wednesday, June 26th, 2019 AT 12:03 PM (Merged)
Tiny
CMCGAHEE
  • MEMBER
  • 1 POST
  • 1999 DODGE DAKOTA
  • 4 CYL
  • 2WD
  • MANUAL
  • 200,000 MILES
Just had three freeze plugs replaced on right side of engine (below manifold). When we got it back, card drove home, but wouldn't shut off. Ran for 15 minutes before stopping on its own. Now it will crank, but not start. Odometer flashes 4 times then shows "No Bus". Checked connections I could see, all seem ok. Unplugged negative terminal, removed all three connectors from PCM, to no avail. Help?
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Wednesday, June 26th, 2019 AT 12:03 PM (Merged)
Tiny
JACOBANDNICKOLAS
  • MECHANIC
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The no bus indicates there is no communication between the computer and its accessories. Recheck the PCM plugs for damaged pins, corrosion, and make sure it is tight.

Also, are you getting either spark or fuel to the engine? Also, what caused it to finally shut off? That sounds like an ignition switch problem.
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Wednesday, June 26th, 2019 AT 12:03 PM (Merged)
Tiny
HELENJAY
  • MEMBER
  • 10 POSTS
Hey joe. Ok I replaced the fuel pump relay ran it for 20min they never got hot. Woo hoo. Im going to take it for drive later this evening when traffic dies and see what happens. But so far idling it ran

i will give you up date tom

thanks joe very much I hope we got it
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Wednesday, June 26th, 2019 AT 12:03 PM (Merged)
Tiny
HELENJAY
  • MEMBER
  • 10 POSTS
Hey joe. Well that is not fixed at all. Barely out my drive way and it was dead. 10min cool down. Then started again went for half hour dead again. Half hour cool down that time then started again. Brought home and wont start now.

Everytime its died it has said "no bus" code again

im ready to give up
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Wednesday, June 26th, 2019 AT 12:03 PM (Merged)
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,709 POSTS
The no bus is indicating there is no communication between the computer and its components. There has to be a wiring issue between the two. I'm wondering if the fuel pump is bad and drawing too many amps. That could be why the relay is overheating. God, this would be so much easier if I was there to help.
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Wednesday, June 26th, 2019 AT 12:03 PM (Merged)
Tiny
HELENJAY
  • MEMBER
  • 10 POSTS
Hello joe

so I dropped my fuel tank today to look at pump.
After it was done there was 2 wires unplugged the main power wires. The othere 2 are bare wires fuel tank is fukk of dirt, and the filter on bottom of pump is dirty as hell. So im oredering one now monday so I think that maybe the problem
after I get back in I will let you know how it works or what.

I have appreciated all the help and ideas so far.
Jason
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Wednesday, June 26th, 2019 AT 12:03 PM (Merged)
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,709 POSTS
That sounds like the problem. Let me know how everything works out for you.

Joe
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Wednesday, June 26th, 2019 AT 12:03 PM (Merged)
Tiny
CORNELLHART
  • MEMBER
  • 1 POST
  • DODGE DAKOTA
2000 dodge dakota sport 2.5L. Truck will not start and this flashes on the odometer. What does this mean?
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Wednesday, June 26th, 2019 AT 12:03 PM (Merged)
Tiny
ANTH
  • MEMBER
  • 8 POSTS
NO BUS is computer related I have a computer programmer and when its programming no bus flashes on my cluster my guess is ur computer needs a program
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-2
Wednesday, June 26th, 2019 AT 12:03 PM (Merged)
Tiny
HELENJAY
  • MEMBER
  • 10 POSTS
Hey joe
is it better just try and figure which wire goes where on here before I get a new one? Or should I just order a new one?

Colors that are unplugged are black and orange the2 in the middle plugged in ar black/green strip and pink/black strip
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Wednesday, June 26th, 2019 AT 12:03 PM (Merged)
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,709 POSTS
I just tried to find a wiring schematic and found every wire in the vehicle except the pump. Are the wires that are disconnected the same as the ones on the pump?
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Wednesday, June 26th, 2019 AT 12:03 PM (Merged)
Tiny
HELENJAY
  • MEMBER
  • 10 POSTS
Well my friend joe.

I got this truck runing last night I went 4 hours to get a pump lol. Anyway so far so good. Ran it last night ent for half hour drive. This am I went fir a hour drive, washed it and it still running woo hoo

i got little more power too of the line, I like that
its idling better and the relays are cool.

As I said before I really appriciated the help the answers and ideas, I sure hope we got it.
As I get out of my finacial situation here I will send you some money for all your time and thoughts.
I will stay in touch if I have any more trouble but I think we got it

thanks again joe and ttyl

jason
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Wednesday, June 26th, 2019 AT 12:03 PM (Merged)

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