DBC File, AEM CD Series dash Conversion

[KingChuck24]

Hello Everyone,

I found a cheap used AEM CD5 dash and bought it and I am now trying to connect it. I was wondering if anyone had already mapped out all of the different CAN channels in a DBC file? I have looked through the forum and have not found anyone that has uploaded one.

If there isn't anything out there I was going to follow Dan Dulac's process which seems straight forward enough.

I am also using the CAN High/Low off of the OBD port with a passthrough connector. Does anyone know if this will work or do I have to pick up the CAN from some other wires? When I was playing with the dash I was trying to get it to log but it wouldn't log anything which leads me to believe I may not be able to use the OBD port. I wasn't going to rule this out until I got a proper DBC file though.

I'll try to post my whole process and if I get it working will make a little tutorial and post my DBC file so anyone should be able to replicate it in the future.

 

[ennonne]

CAN wires in the OBDII should be work. There's a 120k terminating resistor in the ECU, and one in the electric power steering module. You need two terminator resistors (one at/near each end of the network) or it won't work. And of course, the network needs to be intact.

What modules are in your car?

And on the DBC/GMLAN in general. The messages used by the Cobalt/G5 weren't used in a lot of cars. HHR, Solstice/Sky, and a couple others. Google isn't much help for the right addresses for the Cobalt. If you find some addresses that don't appear to be working, it's probably the wrong info. Once you can see some CAN traffic, you'll be able to see some messages IDs and focus on those when looking for information.

This is out on the web, from an '08 Solstice GXP as an example:

13:51:32.874 --> 110 8 0 C C7 0 0 26 27 0
13:51:32.874 --> 120 8 3 5A 23 58 6 C2 3 23
13:51:32.874 --> 2F2 7 10 26 FF FC FF EC 0
13:51:32.874 --> 2F6 5 23 A5 C 0 0
13:51:32.874 --> 380 8 12 1A 10 0 F0 0 FE C
13:51:32.874 --> 128 4 3 3 1 0
13:51:32.874 --> 308 8 0 37 0 0 0 0 FF 1
13:51:32.874 --> 124 5 0 13 58 3 5A
13:51:32.874 --> 140 8 3 20 60 6 FC DF 0 0
13:51:32.874 --> 128 4 0 3 0 0
13:51:32.874 --> 670 8 47 32 4D 47 33 35 58 34
13:51:32.914 --> 124 5 0 13 59 3 5A
13:51:32.914 --> 130 5 9C 5F 81 7E 80
13:51:32.914 --> 128 4 1 3 3 0
13:51:32.914 --> 144 2 F FB
13:51:32.914 --> 410 8 0 0 0 98 40 0 0 0
13:51:32.914 --> 124 5 0 13 59 3 5D
13:51:32.914 --> 140 8 3 20 A0 0 FC DE 0 0
13:51:32.914 --> 128 4 2 3 2 0
13:51:32.914 --> 388 6 0 47 0 0 0 10
13:51:32.914 --> 124 5 0 13 59 3 5D
13:51:32.914 --> 380 8 12 1A 10 0 F0 0 FD D
13:51:32.914 --> 128 4 3 3 1 0
13:51:32.914 --> 140 8 3 20 E0 0 FC DD 0 0

 

[KingChuck24]

Got in contact with AEM support and basically learned that the dash cannot interact with J1850 VPW in any way and only does ISO 15765-4. My 2006 cobalt is on the J1850 protocol so unfortunately it wont work for me. I am going to keep it as a lap timer and a secondary CAN device for monitoring other sensors until I go to a standalone ECU that can properly run it.

 

[ennonne]

J1850 is the OBDII protocol. The GMLAN is different. That's what is sampled above. Each line is a message. I know the early Cobalts were different, but I was thinking the '06 would be like what I'm used to. I need to double check that....