Posts: 4
Joined: Sun Jul 21, 2019 4:03 am
Delivery Date: 21 Jul 2019

HVAC LIN communication (Gen1)

Mon Jul 22, 2019 3:48 pm

Hi all,

I'm a newbie who likes to tinker and fix stuff.
Has anyone on this forum looked at the LIN comm's on a Gen1 between the AC Auto Amp and the PTC heater and the A/C compressor?
I'm interested in this for repair as well as for re-use of these components in other applications.
I'm trying to understand the messages going back and forth but it's taking a lot of time and effort.


Posts: 76
Joined: Fri Sep 06, 2019 7:58 pm
Delivery Date: 02 Sep 2019
Location: Hartland, MI

Re: HVAC LIN communication (Gen1)

Tue Sep 24, 2019 5:42 am

Hello Cees, any luck with this, or anywhere you've found more info on the LIN messages to PTC? I would like to figure out more about how or why my PTC heater is not working, and apparently has worked intermittently. Thanks, Dale
2014 Leaf S Plus :o (12/2019 62kWh swap!)

Posts: 4
Joined: Sun Jul 21, 2019 4:03 am
Delivery Date: 21 Jul 2019

Re: HVAC LIN communication (Gen1)

Thu Nov 07, 2019 9:19 pm

Hi Daklein,

No progress I'm afraid. This is what I know.
Gen1 PTC heaters fail from time to time.
It's typically the same components that fail on the circuit board.
Whether these components are the cause or the victims, I don't know.
Boards that failed show a specific bit as high in the LIN communication, compared to boards that are OK.
I suspect the bit is set in the board's microcontroller and can't be reset, to avoid damaged boards from being repaired and re-used.

Since your board works intermittently I think you're dealing with different failure mode than I am.


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