Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

CCD Bus system

I looked up a couple trouble codes on ALLDATA and was wondering if anybody could decipher what the following means:

- No CCD messages are recieved from the BCM (Body control module?) for 30 seconds.

- Theory of operation states the PCM and BCM communicate across the CCD bus system. Information is needed from either module to operate their respective systems.

The code itself is a 66,shorthand form CCD bus system. Is CCD cruise control drive?

Anyways, if anyone has any insight into what the above means, I’d appreciate it. Thanx.

I conclude this is OBD2 right. What type of car? I suspect this is some manufactures protocol (GM uses UART, FORD uses SCP with audio data on a ACP link)

Then again it could be Cruise Control Device.

CCD bus, I think is Chrysler.

CCD actually stands for Chrysler Collision Detection.

What exactly is the problem that you’re having? CCD is just the serial bus that Chrysler’s vehicles use to shuttle around information among the transmission, BCM, and PCM. (I don’t believe that “collision” in this instance refers to a car crash, but rather communications collisions on this network.)

So yeah, 66 is a generic code for “things aren’t talking”, either due to a module failure or connection failure.

Sorry, my cars a Dodge Intrepid (95). What is a bus system?
Could the module or connection failure be faulty wiring or shorted circuits? I posted a question not long ago concerning a delayed start but when the 66 code came up CCD bus system, I didn’t know what that meant.

Right. In this case a bus is just a communications line in the car. It’s a serial bus, just like the USB port on your computer. For the sake of this conversation, we can just refer to it as the physical connection among several components in your car.

It links the body control module to the power train control module, and those two things to the transmission, and those three things to the instrument cluster. Code 66 just means that information is not passing among some of those devices. Unfortunately, it’s not more descriptive than that.

So yes, it could be faulty wiring, or it could be a faulty electronic module that the wiring connects to. A little more information on what symptoms you’re having would do a world of good.

Ok, but I do not know if the symptoms are related to the code. I said in a previous thread the issues are with a delayed start. I start up the car (this has been happening for over a year) and their is a 5 to 10 second delay for the car to start up- that includes lights and radio. After I have been driving a while during the day, things are fine. The delayed start only seems to happen when the car has been idle usually overnight or the whole day. Other people have suggested it could be related to fuel pressure, fuel pump regulator or check valve.
My friend’s dad did put in a “new” (junkyard peice) pump two summers ago because of a leak.

The problem with the communications buss may be related to the power problem you are having with the radio and lights. I would check to see what is causing the trouble with them first. If that doesn’t fix the trouble and the buss wiring to and from the BCM is ok then you may need to replace the BCM.

Would I have to go to the dealer to replace the BCM? My friend’s dad usually does my repairs. He used to be a mechanic. How invasive a procedure is it?

You might have to. I think it will depend on the options installed in your car. They may have to be programmed into the replacement box. If you do need another BCM you may be able to get a rebuilt one at a parts store for a far less cost over the new cost price at the dealer.

You first need to find out if the trouble is really inside the BCM before saying it is bad. This will require some troubleshooting. If you are going to have someone look at the problem it would be wise to invest in a service manual or purchase service data from

This article could give you some clues to a fix:

Good link.

Thanx for the link hellokit

As always, more good info! Thanks Hellokit.

All of the control modules talk among each other over the CCD bus lines. If one module doesn’t hear from another module that something has been done, that module won’t order some action (like, say the transmission control module (tcm) doesn’t get word from the power control module (pcm) that the vehicle speed is right to lock up the torque converter, that torque converter lock up won’t be ordered by the tcm).
The CCD bus lines are two twisted-pair wires that go to all the control modules (tcm, pcm, bcm, etc.). The bus + wire is violet/brown (VT/BR). The bus - wire is white/black (WT/BK).
You want to check that the wires are whole. To do that, check the wires at each end, between two controls modules at a time. Disconnect the battery. Disconnect the electrical connectors from the control modules.
The bus + terminals are: PCM 26, TCM 43, BCM 8, diagnostic connector pin 4. The bus - terminals are: PCM 46, TCM 4, BCM 7, diagnostic connector pin 3.
Using a digital multimeter, read the ohm resistance at two ends of a wire. For example, read ohms on the wire end at PCM 46 and the other end of the wire at TCM 43. The ohms should be under 5 ohms.
Check the wiring before considering replacing any parts.