I've been getting the no bus code intermittently for the past month. Truck runs normal but driving without guages is frustrating. My mechanic checked for loose connections and found none. He told me the PCM was bad and that DC is notorious for having poor PCM's. The price for new PCM is 850.00 from local Dodge dealer. Do I have any other options or am I stuck in purchasing a new PCM from the Dodge dealer? Any suggestions or comments would be appreciated. Thanks

 

[align=left]pulled this from v8performance. i know it says 99 dodge dakota but i can do the same self diag with my 01 ram. maybe it'll help.[/align][align=left][/align][align=left]How to check codes on a 1999 Dodge [/align][align=left]



MESSAGE
DESCRIPTION
CORRECTION

110
A failure has been identified in the cluster CPU, RAM, or EEPROM.
Replace the faulty cluster

900
The CCD data bus is not operational.
1. Check the CCD data bus connection at the cluster.
2. Check the cluster fuses.
3. Check the CCD data bus.
4. Check the CCD data bus voltage.
5. Check the CCD data bus terminations.

920
The cluster is not receiving a vehicle message from the PCM.
1. Check the PCM software level and re-flash if required.
2. Use a DRB scan tool to verify that the vehicle speed message is being sent by the PCM.

921
The cluster is not receiving a distance pulse message from the PCM.
1. Check the PCM software level and re-flash if required.
2. Use a DRB scan tool to verify that the distance pulse message is being sent by the PCM.

940
The cluster is not receiving an airbag message from the ACM
1. Check the CCD data bus connections at the ACM.
2. Check the ACM fuse.

950
The cluster is not receiving an ABS lamp-on message from the CAB.
1.Check the CCD data bus connections at the CAB
2. Check the CAB fuse.

999
An error has been discovered.
1. Record the failure message.
2. Depress the trip odometer reset button to continue the self diagnostic test. [/align]

 

Click Here: http://www.trademotion.com/partlocat...mp;catalogid=1

Looks like it's under $400 for your application.

Also ... the PCM is considered part of the emissions control system so it MAY be still covered under that systems warranty (usually longer than the rest of the vehicle ... by federal mandate).

 

timwag2001- Thanks for that information. I believe the code that came up was 1687.

 

TMS Bill- Thank you for that website and the emissions warranty information. I will check with my local dealership to see if my PCM is covered under this warranty. If not, paying 400 dollars is better than 850. Thank you once again for this information.

 

think before u jump the other day mine came on because i moved the power window fuse to the powerseat location (which i dont have) to avoid putting the newly tinted windows down. it could be a bad fuse or a missing fuse check first. this is a thread that i started read dh vaughns story at the end

https://dodgeforum.com/fb.asp?m=660681

 

Check the grounds under the dash. You may have a ground that popped loose from its crimp terminal.

 

i'm betting a new expensive pcm is not going to fix the problem.
from pavementsucks...

1687 No messages received from the Mechanical Instrument Cluster module.

http://www.pavementsucks.com/forums/...hp?topic=71595

do the instrument cluster test descibed by tim above while everything is working.
then when you get a no bus failure, try it again to see if you get a msg, or different msg.
my speedo intermittently quit working last summer. when speedo worked, it passed the test, when speedo was dead, it would not move during the gauge test. that told me to replace the cluster. (ebay) not related to your problem but just an example of trying to get the truck to tell you what in the heck its doing.

another thing to try. i have buddy with a Chev Tahoe. every once in a while it sort of goes haywire and stuff won't work. he grabs all the wires that plugs into his pcm and shakes them hard. it starts working again...

 

stop. what i dont lik about timwag2001 list is your truck is a pci bus system not a ccd. the no bus is a module communication failure. the system is a pulsing signal from 0-7.5 volts. the wire is white/purple or purple /white tracer. while this no bus is happening check this circuit if ok bad cluster if not, any module on the bus ( 1 of 36 possible by options) or a bad,shorted or open wire. 80% of these i have seen is the cluster or circuit board depending on the year and model.

 

Thank you everyone for your suggestions and advice. You guys are great in trying to help with this frustrating situation. I'll forward these suggestions to my mechanic since I'm not mechanically inclined but I will check for loose connections under the dash regarding the grounds. My mechanic did state that he checked quite extensively hoping to find something pretty minor or simple that could be causing the no bus/1687 code but he concluded that the PCM is going bad and that is not uncommon for DC vehicles. He is a very knowledgeable and trustworthy mechanic. My other concern is if it is possible that the Superchips could becausing this problem. I've noticed several times when changing my tune from performance to towing and vice/versa that my guages at times don't work and the lights on my dash are on when cycling through the programming procedure and when the tune is finished and the Superchips is disconnected everything is normal. Also, during the tuning process, I can hear a lot of clicking underneath the hood of my truck like something is being turned off and on until the tuning is done. Just a thought regarding the Superchips. I hope not because I love this mod on my truck. Thanks once again to all who have responded.