Engine/Transmission (1998.5 - 2002) <no bus> message on odometer & all OEM dashboard gauges dead?

[JohnMcIntyre]

I have a 2001 1 ton 2nd Gen 3500 truck which has been working perfectly since I took delivery brand-new just over 5 years ago. I am currently in England and the nearest Dodge dealership is about 4,000 miles west of my current location, so options are pretty limited.



This afternoon my dashboard display went crazy, and displayed both the Transmission and ABS warning lamps, plus speedometer, revcounter, oil pressure, battery and temperature gauges are all no longer registering.



In addition the digital odometer, initially displayed the current mileage (118397) and then flashed off to be replaced by the words < no bus > which holds steady.



I won't be able to check out the details of any MIL diagnostic code until tomorrow (Monday) but would like to know if it is okay to drive the truck to the garage then without doing any harm? The engine starts up and runs okay for now, but I don't want to take any unneccessary risks.



All information and advice gratefully received.



Thanks!

 

[JohnMcIntyre]

Update - P-Code diagnostic = P1698





Apparently this means there is no CCD/J1850 message from the TCM (presumably from/towards the PCM?). the service manual does not make that level of distinction.



The more descriptive explanation suggests that there are no CCD/J1850 messages received from the electronic transmission control module (EATX) or the Aisin transmission controller.



Any ideas anyone?



JMc

 

[Marco]

CCD bus

Yep John,

that is the CCD bus that's missing. That could be anything from shorted CCD bus wires, bad grounds, a faulty electronic module . I think a few guys on here had a similar problem. The culprit was the "connectors" behind the instrument bezel. First of all I'd try to pull that one and clean/grease all the contacts.



Other than that it becomes a little more complicated. You will need to check the voltage on the CCD bus cables. If my memory serves me right then there should be something like 2. 5 Volt on each cable. One of them two should be a little higher than the other. If no voltage, then start pulling plugs from the ABS/ECM/PCM and see when the voltage comes back on.....



The CCD bus get's it's voltage bias which comes from the central timing module ( That thing is under the dash right side of the drivers knee polster ). I think those have gone bad too a few times.



Anyway, you can drive the truck even without the CCD operational, no harm to the engine. The ECM does not need the CCD to operate the engine.



If you're not able to find what's wrong with it, any Chrysler dealer should be able to help. CCD has been the proprietary bus used in all Chrysler vehicles up to MY 02. They should know about it... .



Hope this helps a little.



Marco

 

[JohnMcIntyre]

Cheers Marco! Good to hear from you again! Do you happen to know what the Chrysler part number may be for the CTM module, and how to verify easily if it's the symptom or cause? There are Chrysler dealers in the UK so they may have a common/standard part that srvices the data bus itself.



Do you know if there a specific page in the Factory service manual or Service supplement manual for 2001 model year trucks that show this CTM module, in-situ or standalone, so I know what I'm supposed to be looking for/at?



Cheers.



JMc

 

[Marco]

John,

before you start to look at the CTM, try to pull out the instrument panel and give the connectors a look! It's a maybe 10 minutes job! It's NOT said that the CTM is the fault! Could also be the CCD wires... Have you done any work lately on the truck?... .



Marco

 

[RamSport01]

Might not be a help, but a buddy of mine had a '99 gasser that he didn't know had a broken wire running along the frame by the engine and it displayed NO BUS on the odometer. Truck would start and run sometimes then not at all others, 6 dealers couldn't figure it out, truck was in the shop for 9 months. An old timer stopped by one day and fixed it in 5 minutes.

 

[JohnMcIntyre]

OKaaaay! will pull the dash tomorrow and check out the wires/connectors/bus-CCD voltages - to answer your other question - I ditched the OEM POC liftpump at 110k coz I was living on borrowed time and went the FASS2 route last Fall and now I'm not looking over my shoulder all the time.....



I also just got me a complete 2nd set of 19. 5inch rubber all round in readiness as the original 19. 5 inch tires with 100k miles on them need to be re-cut soon as they get near to their 3mm minimum tread depth, so I can get another 50k miles from each tire.





What you upto with your mad ECMs?

 

[wtfd6]

if anybody should know about this stuff it would be marco. i must have been mistaken when i thought that the mic biased the bus. i am just learning how to troubleshoot these problems.


mark

 

[darkhorse]

Do you know if there a specific page in the Factory service manual or Service supplement manual for 2001 model year trucks that show this CTM module, in-situ or standalone, so I know what I'm supposed to be looking for/at?



Cheers.



JMc[/COLOR][/SIZE][/FONT][/QUOTE]



The CTM is a fist sized black plastic box with one or two large multi wire connectors on it. It's just to the right of the steering collum. (assuming left hand drive) Just pull off the bolster under the collum & you can get at the retaining screw.

 

[Mick2500]

John,

Read this:

https://www.turbodieselregister.com/forums/showthread.php?t=127041



Mick

 

[jmtandem]

john,



went through this with our '01. Dodge had it three weeks and it was covered under warranty. It was a short in the air bag system. Also, if you get the front brake pads replaced, and the fluid is pushed into the abs, it can display some of the same symptoms. good luck.

 

[Marco]

Any news John?

 

[Mick2500]

This really belongs in the

2nd Generation Ram Forum (NO engine/transmission discussions) Forum.



John,

Did you find the CCD+ and CCD- lines? With the batteries disconnected you 'should' be able to put an Ohmeter on those two lines and measure 120 Ohms.

That is how they terminate the CCD bus. If you have an overhead console and it also indicates "CCD" then the problem is NOT in your dash.

The dashboard diagnostics are a good way to eliminate the dash as the problem.



Mick

 

[JohnMcIntyre]

A little bit older and wiser....



Problem sorted..... finally!!



Dodgy connectors behind the instrument cluster in the dashboard were to blame. Plus for good measure, I repaired some connenctions near the PCM under the hood that were obviously corroded and it's all working okay now.



Note: Working behind the dashboard is very fiddly/awkward!!!



JMc