Time/Clock on Dodge CAN Bus

Ideas and discussion of what to do with the CAN Bus ( i.e. XMDirect, iPod, Carputer, etc... )
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nemiro
CAN? Tin or aluminum?
Posts: 35
Joined: 2015 Feb 07 20:06

Time/Clock on Dodge CAN Bus

Post by nemiro » 2017 Nov 06 21:47

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
CAN? Tin or aluminum?
Posts: 35
Joined: 2015 Feb 07 20:06

Re: Time/Clock on Dodge CAN Bus

Post by nemiro » 2017 Nov 06 23:09

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
CAN? Tin or aluminum?
Posts: 35
Joined: 2015 Feb 07 20:06

Re: Time/Clock on Dodge CAN Bus

Post by nemiro » 2017 Nov 07 19:12

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
Yes, we CAN hack!
Posts: 62
Joined: 2017 Feb 09 23:31

Re: Time/Clock on Dodge CAN Bus

Post by poop713 » 2017 Nov 07 21:07

sick man! great find!!

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