Piston

Thanks guys, I will dive deeper into this before sending out my pcm. I have already done the fuse in the pcm harness but not the WT ground so I think I will do this and the WT at the same time. Thanks so much!

Do you think that this slight variation in voltage could cause the issues I listed? And also have you seen this before?

Hi and thanks, I did let it sit for a few minuted before but just did it again and let it sit with koeo for 15 mins and still had the same readings.

.....also, how crucial is the bias voltages? I have 2.46 on the purple and 2.40 on the white at the DLC.

Hi again folks, Its been a while but I was able to pull the dash and swap over the wiring harness. I did notice a difference in the two harnesses. I got it all back together and really had no change. I noticed that the alternator was now not charging. I have noticed that if I pulled the battery terminals and reattached them, I could fire up the truck and it would act fine. Shut it off and restart and bam, no gauges and no bus and no charging. Wait for 20 mins, re start and everything ok, drive it and the fuel gauge and battery gauge would drop out. At this point, I think the PCM has given up because now I have absolutely nothing - no gauges at all, no bus message, 0920 921 and 999 messages in the self check, no charging, no communication to the code reader. I installed a fuse in the blue wire to the pcm a while back like outlined as well. I put in another PCM from a friends truck (I know they are vehicle specific but what the heck) and I have all gauges but still get a no bus message and the od off light stays on - I am thinking this is a programming issue being from another truck. Sorry for the length but I wanted to post as much info as possible. Any direction is greatly appreciated!

Hi again, Just a quick observation....I havent changed the wiring harness from the original diesel cab yet but today I started the truck to move it and noticed that most of the gauges were working and I didnt have a no bus message. I moved it and the trans engaged in 1st gear as it should and the alternator was charging. I took the opportunity, as I know it would be short lived, and hoked up the code reader and it communicated. I had the following codes: PO253 Injection pump low, 1689 No communication between ecm and inj pump, 1688 Internal inj pump controller fail, 1698 no ccd. I tried to clear and see if any were hard faults but as soon as I shut it off and restarted, no bus was back and I had no communications. My plan of attack is again to change over the harness and if there is still an issue, unplug the other modules to see if any of them are pulling they system down but I wanted to share this info as well to see if anything jumps out at you folks. Thanks again for your help!

I'll squint really hard and look for ya!

Man I haven't head that in years! My dad used to recite that skit when I was a kid before he would chase me through the house!

Thanks! It does make sense. Looks like my Saturday is booked! I will let you know if it clears things up. Thanks again!

Thanks --- just to clarify the PCM is the original from the diesel cab. I think I will pull the dash this weekend and put the original harness in it and see what happens before going any further. Thanks!

Hi. Thanks for the reply, The dash and all wiring inside of the cab is from the donor cab and it is from a 1998 gas truck. I was wondering in the back of my head if I should pull the dash and change the harness over as I still have the original cab. The PCM is from the original truck. Question - I have a friend with some parts - can I borrow a PCM from him to plug in to see if it will do anything differently? I understand that they are flashed to the VIN but will it work at all? thanks again!

Hi Folks, New guy here from Canada. I used to race a Chrysler Cordoba on local dirt tracks and am building an 02 2500 ext cab 4x4. Cheers!

Hi Folks. I am looking for some direction with my no bus issue. I did a cab swap on my 02 2500 4x4 24 valve automatic trans. I just bought the truck and did notice the fuel gauge was acting up before hand but didnt notice anything else but then again I bought it as a project and got right to work. After I got it back together, I would get a few gauges acting up and every 3rd or 4th keystart, I would get a no bus message. Here is what I have now pretty much with every keystart - No Bus message, Alternator not charging, None of the gauges are working, Starts off in 2nd gear - Limp Mode?, no communication with code readers, O/D off selector not working, dash warning lights on, codes 920, 921, 999 on the odometer. I checked the voltage on the #3 and #11 pins of the OBD connector and have 2.44 on pin 11 and 2.45 on pin 3. I understand this is a communication error between modules and could also be an issue with the cluster as well but would like to know where to go from here. Any advice or direction would be greatly appreciated! Thanks!