1989 SMEC to 1993 BCM Questions

[mdfoxw2001]

I hope this is the correct forum.
O.K., I know there is a big discussion in the other turbo/VNT forum as the contribution of the Vehicle Speed Sensor input to the calculation of load. There was some information as to how it functioned also. The two early 90’s units that I took apart used a sealed magnetic reed switch and a wheel with, if I remember, 8 small magnets. This would give 8 pulses per revolution. I have a 1994 Acclaim system with a different design w/three wires. My 1993 LeBaron has no VSS at all. The LeBaron has the A-604 so I assume that the speed calculation is based on the output turbine speed sensor. Please, could someone explain it? This leads me to the purpose of this post. I have another 1993 LeBaron, in pieces, and the drivetrain components from a 1989 Spirit T-I, firewall forward. I want to put the two together. Since the combo would be 1989 SMEC w/custom harness and 1993 Dash harness & BCM, what issues will arise with the BCM. I have worked out most of the other issues. Here is my thinking; the mechanical cluster should work as there will now be a VSS in the 1989 harness and no transmission computer. On the other hand, the 1993 had a different BCM than earlier J-Bodies, I know the interior lighting control was one issue. I know there was also a change in the CCD coding. I know very little about this. What my concern is, will the BCM pose any problems? I can see that it might no longer be able to store the mileage or operate the automatic door locks. It was suggested that the speed signal protocol might even be the same through these years. Does anybody know? I would appreciate any help. Thanks.

[Shel-Game]

Does the '93 have ABS? If so, the ABS system has speed sensors at the wheels. Also, the '93 uses the CCD bus (a way for all the different computers to exchange data) and the ABS computer probably sends the vehicle speed to the SBEC-II via the bus.

The '89 T1 SMEC does appear to have an implementation of the CCD bus, but I don't know if the protocol is the same as the '93 (but I really don't think it is).

I'm sure you could use a T1 SMEC to run the car, but I doubt you could get the dash, BCM, and ABS computers to work right after.