Time/Clock on Dodge CAN Bus

[nemiro]

I have a project (which some of you have PM'd me on) to be able to 'create' your own CAN-B Bus inside a vehicle that does not have it. I am using an Arduino (Teensy) based solution, and a custom PC Board. Works like a champ!

I am using a Chrysler MyGIG RHR radio, and despite it working properly, including satellite radio and GPS SATNAV, the clock always stays at 12:00, even when you attempt to set it manually. I have tried two different RHR's, for reference, same result on each. I am guessing that the original application sent a time keeping CAN-B message to the radio, and that I am not replicating that, so the clock will not work properly.

Does anyone out there have any insight to this? Thanks!

[nemiro]

Well, found where the car is sending the time to the radio:

id 0x03EC, msg length 03,

byte 0: Hour
byte 1: minutes
byte 2: seconds



I spoofed some values, and sure enough, it displays it. What I am not finding yet is where the radio is updating the car, via GPS.

[nemiro]

Disregard earlier comments. OK, found where the radio sends the data out (provided it has a GPS Signal, have not tested on a 2009+ radio from a "time dependent " system). 2008 down cars do not have a clock module in the vehicle's systems, hence clock issues when you install a later model REN/RER/RHR/RHB radio into an earlier car.


GPS clock output from a GPS equipped radio:
ID: 0x00F0
byte 0: unknown (time zone?)
byte 1: hours (24 hour)
byte 2: minutes
byte 3: seconds

Processing this data, and then spitting it right back at the radio via message ID 0x03EC gives a correct clock display.

Interestingly enough, the RHR will not allow you to save a user entered time, if it does not receive a continuously updated time. ie, if nothing is coming in from 0x03EC, and it is not changing with seconds, you cannot enter a USER CLOCK setting, and have it work. Weird.

[poop713]

sick man! great find!!

[BiggRanger]

I've been working on the same thing. 2008 Dodge Durango, the SKREEM module is the time keeper, it broadcasts the 0x3EC message, and also listens for the 0x0F0 message.

When setting the clock radio the 0x0F0 message goes from 00, 00, 00, 00 to 0x03, HH, MM, 00. After the clock is set it resumes the 00, 00, 00, 00 broadcast.

For more information see my Chrysler radio project here -> https://github.com/BiggRanger/Chrysler- ... -Interface

[nemiro]

Nice! I have been using my Teensy 3.2 based setup for more than two years, but your setup offers the advantage of not needing to build much, if any, custom hardware.