No Bus Problem

2002 DODGE DURANGO
200,000 MILES
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BAUMERSK
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Have "no-bus" code on odometer. Will crank but no start. Will not start on ehter. Fuel gauge indicates no gas but tank half full. Idiot lights, odometer and park, drive indicator works on cluster. Does this mean instument cluster module ok? Dome lights, chime warning for key in place. Does this mean the central timer module ok? Have 4 volts in 5 volt PCM circuit. If unplug the crank and cam sensors individually, voltage increases to 4.33. If unplug other sensors on circuit, voltage increases to 4.05. The bus line has only 0.6 to 0.9 volts. If I unplug the transmission control module I still get the "no-bus" code on the odometer and the voltage in the bus drops to 0.3 to 0.5. Have already cleaned the grounds on the right side fender for the PCM and Trans Control Moducle without any change. Have cleaned the negative baterry cable ground on the left side fender and the positive battery cable to the under hood fuse box without any change. Any ideas?
Feb 2, 2012 at 6:05 PM
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MERLIN2021
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It may be an actual broken bus wire and your modules are not talking to each other. I recommend a CAN scan

https://youtu.be/InIlnsjOVFA

This video will show you how
Feb 2, 2012 at 8:16 PM
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BAUMERSK
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2002 Duarango with "no bus" code on odometer. No spark (won't start on ether). No codes on rented Auto Zone scanner. Crank sensor was shorted, bringing down 5-volt PCM system. Replaced sensor and now have 5 volts in PCM circuit, however still have no bus code and will not start. Does PCM system have a fuse and can it be a problem since there are 5 volts? Does the PCM code have to be deleted from computer for car to run and if so how to do it? Have had battery disconnected with no effect.
Jan 6, 2020 at 4:42 PM (Merged)
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RIVERMIKERAT
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Disconnecting the battery can erase codes in volatile memory, but not in non-volatile memory. The scanner should have an option to erase or reset codes. Make sure the coil is receiving power.

Download the image attached. Then change the file extension to PDF and open it. It is the schematic for the computer data bus. I had to upload it as a jpg since our system doesn't allow pdf files yet.
Image (Click to enlarge)
Attached Media
Jan 6, 2020 at 4:42 PM (Merged)
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BAUMERSK
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Found crankshaft sensor was shorted, bringing down 5-volt PCM system. Replaced sensor, now have 5-volts in PCM system. Still have no start and the no bus code on odometer. Do I need to clear no bus code? Now that I have 5 volts in PCM system, is there anything else that could cause the no bus code to remain? Help, I'm out of ideas. Thank you.
Jan 6, 2020 at 4:42 PM (Merged)
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ASEMASTER6371
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you may have a cluster issue separate from the no start.
back to basics, do you have spark, fuel pressure and compression??
is there any codes stored??

Roy
Jan 6, 2020 at 4:42 PM (Merged)
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JAMIE HAND
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My vehcile just stopped running. Gives a BUS code. I have looked at all of the sensors and fuses. Everything seems to look okay and test okay what should I do?
Jan 6, 2020 at 4:42 PM (Merged)
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HMAC300
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bus connections are several modules and one is causing the problem. you need a professional scanner to check this. so a trip to your favorite shop is in order.
Jan 6, 2020 at 4:42 PM (Merged)
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LARRY789
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i was driving my car and then all the gears were selected at the same time and then it said no bus on the odometer, and then all my gauges turned off and the dash borad lit up like a christmas tree but the engine was running fine and the brakes were working
Jan 6, 2020 at 4:42 PM (Merged)
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JACOBANDNICKOLAS
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The no bus signal indicates the computer (PCM) has lost communication with its components. Wiring harness to the PCM to make sure nothing is loose or damaged.

Let me know what you find.

Joe
Jan 6, 2020 at 4:42 PM (Merged)
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RANGOMAN
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I turned on my durango and the usual lights such as abs, air bags, seatbelts etc came on. But instead of going off, they stayed on including the engine light. My fuel, temp,voltage, oil pressure, etc guages bottomed out as well. Also, the lever that shows what gear I am in, went blank as well. The mileage gauage alsl shows the mileage, then blinks with the words no bus. Do you have any ideas, as to what may be causing this. Thank you ..
Jan 6, 2020 at 4:42 PM (Merged)
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BLUELIGHTNIN6
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This is quiet common for the later model Dodge vehicles. Your main fuse panel under the hood has a screw in it with a huge contact. Check that contact to see if it has gone bad or is dirty. If dirty, take out the screw and clean connector with electrical contact cleaner. Pack it with electrical grease and put it back in. Then put the screw in and check to see if the issues have subsided.

Hope this helps..
Thanks for using 2carpros.com!
Jan 6, 2020 at 4:42 PM (Merged)
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ACE616
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What causes code P1698 which means No Bus Message from TCM. Could having a car starter installed cause this to come up?
Jan 6, 2020 at 4:42 PM (Merged)
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BMRFIXIT
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[quote:7150de61a9="Ace616"]What causes code P1698 which means No Bus Message from TCM. Could having a car starter installed cause this to come up?[/quote:7150de61a9]


it will help A lot if you tell us what are you working at
Year
Make
Model
Engine size
Tranny ………auto …..or manual
Miles
Thank you
Jan 6, 2020 at 4:42 PM (Merged)
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UP29BALNE1
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The security light comes on and I have tried locking all the doors and unlocking the drivers door with the key first. I hooked up my obd ll and it reads error. The vehicle cranks over, but it is like there is no spark.
Jan 6, 2020 at 4:42 PM (Merged)
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KHLOW2008
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The control modules are not communicating which could be due to security system being triggerred. Check for blown fuses for a start.
Jan 6, 2020 at 4:42 PM (Merged)
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WYLEE
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Car shuts down while driving and sometimes at idle, only when engine is hot, the "no bus" is displayed at the odometer. If I open hood to disapate heat car will restart.
Jan 6, 2020 at 4:42 PM (Merged)
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ROBBIE321
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I had the same problem you can wiggle the middle connection on the computer and it should start back up but that only works to get you home I tyied alot of stuff people told me to try the fact is this is a dodge problem they wont address . But the only fix is to replace the computer. you can find them on the net for about 200 to 400 $ hope this helps you
Jan 6, 2020 at 4:42 PM (Merged)
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DJZBOYZ
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Our 1999 Dodge Durnago was operating normally driving about 40mph, not setting at any stop light. the Engine cuts out and all displays to blank. after coasting to a stop, tried to start it. the check engine light came on, and odoemter changed from displaying the miledge to "NO BUS". the engine would crank, and act like it was not getting any gas. after setting for about 10 min, it started. However a couple of miles down the road, it did it again. I have seen a couple of entries on this site about corriosion on the instument package and a connection or probelm with the on board computor. Can We have any advise on possible repair and cost. thanks.
Jan 6, 2020 at 4:43 PM (Merged)
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LEGITIMATE007
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yeah no bus means there is a communications error from the transmission control module or ecm. I would go to autozone and see what kind of fault codes that the scan will give and bring them back, You may have to replace the computer, or it may just be a simple connection problem with the harnass. but have it scanned and we can take it from there
Jan 6, 2020 at 4:43 PM (Merged)
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DJZBOYZ
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Thanks Legit, it will take me a couple of weeks to get this durango into the shop to check the error codes due to vac plans. Would it be safe to assume if the transmission control module was faulty we would have issues with gear shifting being sluggish or noticable problems shifting gears ? Is there anyway I could easly check the wiring harness connections in the meantime.
Jan 6, 2020 at 4:43 PM (Merged)
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LEGITIMATE007
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you can always check for power and ground with a tester
Jan 6, 2020 at 4:43 PM (Merged)
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FODUS
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Replace the computer. I got mine from AutoZone for around $276 plus a $65 core fee that you get back when you return the old part. The dealership wanted just under $600 for the same part, plus $85 to install it. I was able to install it in around 3 minutes, including unhooking the battery, and I am not a mechanic. It is 3 bolts and 3 electrical connections. If you can't afford the AutoZone price right now try packing ice around the computer to keep it cool. I would buy a bag of ice from a gas station, pour out about 1/3 to 1/2 half of it around the computer, reseal the bag, and then pack the bag around the computer. This worked WONDERS for me until I could buy the new computer. If you need to know where your computer is e-mail me @ [email protected]. Good luck.
Jan 6, 2020 at 4:43 PM (Merged)