[bamman]

There is no BCM in the A body. Bus output to the traveller is handled by the PCM. There is no premium or base BCM or PCM in these vehicles to worry about.

 

[bamman]

The 90 or 91+ FSM makes mention of a CCD based 12 button navigator that would work in Bob Lincoln's case. I have yet been able to ever find one. I'd like one myself.

Marcos, if your interested in selling your 6 button navigator, I'd be interested in purchasing it.

 

[bamman]

That module is called a seat belt control module. It was only used in 94 and 95.

 

[bamman]

Try connecting the data bus wires to the corresponding wires at the PCM instead. Do you need the pinout for that connector?

 

[bamman]

I assume that the bus is OK, but now I'm not so sure, was there any major change in how the bus works from 1989 to 1995 on these vehicles, like the one that Bob Lincoln was up against?

There was a huge bus change in 92. Only 90-91 electronics will work with 90-91 computers. Likewise, 92+ electronics that used the bus will only work with 92+ computers.

 

[bamman]

John-- I have the twisted pair of wires at the TDC, doesn't this mean there must be data there? I.E. how could the pin on the ECU be wired and have no data on it?

Simple, mopar used similar, if not the same, wiring harness for different applications. In an earlier post I mentioned to tap the CCD bus wires at the computer instead. The diagnostic connector that you are connecting it at may not be connected to anything. The transmission diagnostic connector was only used on 4 speed transmissions, if I remember correctly you have a 3 speed. Again, that connector may not be connected to anything.

As for the traveller, what is the part number on it?

 

[bamman]

There is no such thing as a premium and base ECU. There was only a premium and base BCM which the Dodge Spirit never got.

 

[bamman]

To my knowledge there is really only one way of identifying these units, and that is to find the part number on it. 89-91 will be 4437034 and 93-95 will be 4685041. Even if you take the unit apart to look at the circuit board part number, they will be the same.

The manual used to diagnose the traveler would be the Vehicle Communications (CCD Bus) manual. Here is one on eBay:
http://www.ebay.com/itm/321128349125

 

[bamman]

I'm thinking this is the correct CCD 2 traveller. One way to tell for certain is if you can find a chip marked CDP68HC68S1. It should be either a 14 or 20 pin chip.

 

[bamman]

After further research, I think that perhaps the problem here is that the transmission controller is the only source for data to the traveler in this vehicle. Looking at my 1991 Vehicle Communication book, all AA Body Bus Tests start off by asking if the vehicle has a traveler, to which if you answer yes the next step is to inspect the connector at the A-604 Transmission Controller. Really the best way to test this is to connect a DRB II to the CCD connector and see if information is actually being transmitted. Otherwise you may continually spend money on travelers and SBECs that may not work.

 

[bamman]

Doing more research, my 91 Vehicle Communications Diagnostic book shows that there is continuity between the SBEC and the CCD diagnostic connector, so yes there is still hope that you can do this. However, I don't know why you are still getting errors on your traveler.

Another SBEC will not really help. At the very most you can verify which bus your traveler uses if it is indeed not communicating because of a bus protocol mismatch but there is no telling if it will run your car correctly.

As far as using an oscilloscope, you can potentially use one to discern which bus your vehicle is using. The difference between the two buses is simply one has a faster baud rate than the other.

As far as using twisted pair wiring, as long as you twist your wiring at least once every six inches you'll be good to go. Doesn't really matter what wiring you are using.