2002 Dodge Durango no bus error
Asked by Sheri Jun 29, 2018 at 08:18 PM about the 2002 Dodge Durango SLT 4WD
Question type: Maintenance & Repair
I have a 2002 Dodge Durango 4.7l it started stalling
on me and now will crank but not start. I have a no
bus code in the odometer and get 3 codes during
the self check 920, 921, and 999. The check engine
light, check gauges light, abs, and brake lights are
all on. We have already replaced the crank sensor,
map sensor, power steering pump and sensor, oil
sending unit, and changed out the pcm. Before the
car quit auto zone ran it for codes and the only one
was the engine speed sensor but we were told that
couldn't be what's causing these issues. They also
tested and charged the battery it tested bad but
took a charge. Could any of those be the issue or
does anyone have any suggestions on what else
we could try.
19 Answers
Blankpanic answered 6 years ago
its lost communication with the main pcm something is bringing down the computer that controls the engine.
We can't figure out what it could be is the issue. We changed one of the coil packs and the no bus issue disappeared drove the car to the store and it came back. Auto zone ran the codes again and it came back as a bad o2 sensor so we replaced that and some fuses it started running again went to the gas station and the no bus is back
Blankpanic answered 6 years ago
They can be some of the most difficult things to track down. when it shows the nobus does the car still start? if so then it is not an engine computer issue it could be a bad instrument cluster or another module on the network causing the issue.
Did you ever figure out what was wrong? I'm having the same issue.
Blankpanic answered 6 years ago
irod_lightning check your coil packs and spark plugs its a common issue i have seen.
Blankpanic i will take a look into that as well. Another thing i don t understand is why i cannot hear the fuel pump kick in when i turn the key. I'm completely baffled by this. Tried connecting OBD II scanner but it will not detect the PCM.
Blankpanic answered 6 years ago
that almost sounds like a main power or ground issue. you wont get a fuel pump prime if the pcm doesn't power up and you wont be able to talk to it with a scan tool either. i would start with checking all your fuses then the power and ground feeds to the pcm.
My 20amp hazard fuse in the PDC was blown and pulled the bus line down. I did check all fuses for continuity the bad fuse is the square style and made noise while shaking like a bad relay lucky I found it. Solved the problem be extremely diligent checking fuses this fuse would work work when shaken intermitently. The fuse clear viewing area was not burnt or dis colored. Took 2 weeks and lot checking before I found this POS fuse. Take every large fuse from the hood out and do the what I call the shake test.
I am having the same problem and its the engine computer. The on line cost is 200. My mechanic did s diagnostic check. Goid luck
Blankpanic answered 6 years ago
GuruVC994 what actually failed on your pcm? I haven't actually seen one of these pcm's fail.
Durangodemon answered 5 years ago
There is a spot under dash it looks like a little wire anttenna on it it's black with a red tab pull tab.look at it might be a fuse type thing for cluster or something like that I pulled mine just messing around and it said no bus
You probably have the wrong pcm or it wasn't programmed correctly. The pcm has a serial number on the back on the new on has to much exactly. It must also be programmed at a dealer. I believe they can do it with the pcm out of the truck. I'm not sure if other shops can program the pcm but I'd much rather the dodge dealer program it then a normal shop. Might be a little more expensive but better to have it done right the first time
Blankpanic answered 5 years ago
@Chase the pcm serial numbers are all different unless you meant the part number then i would agree they do have to match. The pcm cannot be programmed outside of the vehicle as the abs also has to be reprogrammed along with the SKIM module you will also need all available keys for the vehicle to be present. I know i have done the reprogramming myself haha.
I have same problem with my dakota has anyone found they problem
rdavidharris answered 5 years ago
There are numerous "possibilities" as to the "fix" for this stupid common problem on these trucks. Keep googling. You will find which yours is. Can be three of four different things. LOL (ridiculous!) Most people on this page are shooting in the dark though - and are not even close to what the real issue is. (PCM is "wrong"???) uhhhh... It's the one that came on the stupid TRUCK!. TRY AGAIN!
Vantheman78 answered 5 years ago
Shake test worked for me...found two fuses that looked good but had a rattling sound to them. Swiped out for new ones and fired right up with all gauges working! Thanks team!!!!
In my buddys case, his stereo harness was cut so he rewired it incorrectly which caused the no bus on odometer. Cranks but no start until he undid the wirings but now the car cuts off if u let off the gas pedal.
For advanced mechanics only. I ran a dc receptacle (cigar lighter) directly wired to my battery, and a +5V cell phone charger modified to attach to the +5V wire on my MAP sensor. This supplied the +5V, cleared the “no bus,” and allowed me to use my BlueDriver to scan the ECU. ALL SENSORS ON THESE TRUCKS WITH SUPPLIED +5V ARE ON THE SAME CIRCUIT. You can choose to use another sensor with a violet and white wire (+5V wire) to do this. I DO NOT recommend attempting to start or drive this way. Just allows you to see what sensor has failed through the ECU, or identify a bad ECU. Again, if you aren’t advanced enough to do this, have a mechanic help or perform themselves. In my case, it was a bad idle air controller. Hope this helps!
Somerandomguy323 answered 4 years ago
On my 2002 dakota 4.7 it was the main pcb. Was 200 dollars from 'car computer exchange' online. The older computer boards in these vehicles have over heating issues.