Hello, I have a 2002 Dodge 2500, 5.9L 24V Cummins that’s been down for months & so far is stumping me. It has Auto trans, 4WD, & about 190k miles. As far as I know it’s all stock except for a FASS DDRP fuel pump. This is a long one, but any help or suggestions would be greatly appreciated!

Truck was running fine & then died. Cranks (spins good), but no start. First thing noticed was fuel pump not running. Then also saw gauges are not working, no wait to start light, & odometer flashes a few times then displays “NO BUS”. It will connect but not communicate with a scan tool. It either displays no communication from module or circuit open (from the airbag module). The OBDII scanner adapter lights up & I have Ign + & ground at the connector.

That of course lead me on a CCD communication path for troubleshooting. I started by disconnecting each module or component, 1 at a time, in the CCD circuit. Got it down to only ECM, PCM, & cluster connected- no change. Went ahead & removed the cluster & still no start. While removing I inspected each connector for damaged terminals, corrosion, or dirt. They all looked good.

I then checked the CCD wiring- for short to each other (the Bus + & Bus - pairs), short to ground on each wire, & short to Ign + on each. No shorts or incorrect continuity found on any of that. I also continuity tested each CCD terminal to all the other connector terminals for each wire. Every terminal has continuity with all others on each of the wire pairs.

I then started checking all the grounds, battery +, & Ign + wires to the ECM, PCM & OBD II connectors, Every one of those tested well (even load testing them). I have also checked all fuses (good).

At some point in there I self-tested the cluster. Every light & gauges seems to function properly. At the end I get 920, 921, & 999 errors in the odometer display. Seems to point to PCM problem…

I have checked battery grounds to body & other points. All OK. I haven’t dug into doing a W-T ground wire mod, but doesn’t SEEM to be an issue with that either. Maybe I’m wrong though?…

There is a ground wire to the block just above the starter & according to wiring diagrams, it grounds the fuel pump, fuel heater, A/C compressor clutch, & the CAN-BUS ground. The wire terminal seems good & 3 of the 4 connectors have good continuity to ground. I haven’t found the Cummins Can-Bus connector to check that. Diagrams show it’s located on front left of engine & has 3 terminals ( Bus +, Bus -, & ground). I’m unsure of where or how to check that….

I pulled the PCM & sent it off for bench test & repair. It was returned saying nothing wrong with it. Next I sent out the ECM. They found some corroded terminals & repaired solder connections. I was hopeful that their findings were the issue, but no change after reinstalling so doesn’t seem to be either of those.

Next I went digging deeper in the CCD system. I’ve gone through some flow charts that don’t seem to show any issues. I’ve read multiple threads on here about CCD & saw posted that you need 2.49- 2.51v on each of the CCD wires to ground. I have 2.45v on each of them. I have a troubleshooting flowchart from Mitchell ProDemand that says I need 1.8v to 2.3v. So I guess I’m in range, but can’t say 100% either.

Swapped PCM with a good running 2001 Cummins 2500, AT, 4WD. Both trucks functioned the same way as before even with a different PCM. This truck still had flashing odometer & NO BUS with the ’01 PCM. The other truck ran fine on the ’02 PCM. So that tells me the PCM in this truck is probably fine.

The only thing that I can think of is to either swap the cluster (but I don’t really think that will do anything) or go back through all my wiring & fuses again in case I missed something. Or I am very open to suggestions if you have thoughts on this? Thanks for any help. I greatly appreciate it.

Edited Tuesday at 04:29 PM2 days by 4x4 Nut

I won't be able to offer any help - I am responding because you haven't received a response yet and I didn't want you to think you were being ignored.

From reading your post it seems that you have been very thorough in trying to get your issue resolved. You have checked everything that I can think of that needs to be checked.

Maybe @Mopar1973Man will respond now that I have flagged him. He is knowledgeable in this area.

• John

Sorry been on the road limited cell service.

My suggestion at this point I would consider contacting Auto Computer Specialist and have the PCM and ECM tested. Something is wrong if the wait to start does light up, fuel pump not bumping at key on. Then the PCM creates the CCD bus so. Wiring on the CCD would need to be checked for sure. Bias voltage is not correct even after removing modules.