EVIC temp differences (different topic!)

[Atrus]

I have to believe there's SOME way to get a pre-2004 EVIC temp to work in a 2004+ KJ with the proper hammer ;-).

In a post, I stated that I thought I read something in the BUS system changed (not meaning the protocol or anything, just that something changed to where the EVIC's temp features aren't interchangeable). Marlon had said "The BUS is the same. The way the message is delivered to the EVIC is different".

Does anyone know what changed? I would almost think that a reflash of the EVIC's firmware would allow for the change as the wiring and hardware appears to be the same. Has this been attempted?

I've got a friend that is decent at screwing with this stuff. I want to see what his thoughts are on it, but I'd like to gain all the information I can about what exactly changed. I'd love to find a solution as I got a killer deal on a 2003 homelinkEVIC ($20 for the EVIC, bracket, and 12" of harness!) and I'd like to get the temp working too (if at all possible)

 

[Dave]

I don't know the answer to your question, but if you buy that EVIC before it is sold to someone elce, and afterwards find out that it doesn't work in your application, I'm sure you can sell it and get your money back + a little more.

Just a thought.

Dave

 

[Atrus]

Thanks Dave,

I have the 2003 EVIC up and running. Picked it up at 11:00 on Sat and had it installed shortly thereafter. I love it, and I am fine with not having the temp readout. I'd like to have it work though, and this is just a challenge to me to try and find a way

If I stumbled across a 2004+ unit for the right price, I'd buy it and resell what I have.

 

[Marlon_JB2]

FROM WHAT I CAN REMEMBER:

The '02-'03 Liberty EVIC got its temperature sensor information from the Body Control Module (BCM). In these year Jeeps, you also had to buy the temperature sensor, which was not standard, but the wiring was. It plugged right in.

'04+ on, and probably including '08.. the temperature sensor became standard and has more "use" than it used to, can't remember exactly what it's used for, and now the EVIC grabs the temperature from the Engine Control Module. (ECM)

What did your EVIC say in regards to average MPG when you plugged it in?

 

[Atrus]

Average, I don't remember. I reset everything. It currently reads about 15.4mpg. It's going up as the miles drives has increased. Cold starts and short trips over the past two days destroyed the milage (started at 4.2mpg!).

Yup, the sensor is present in my 2007, I checked that a while back. Really, you'd think the change would be possible via a firmware upgrade. The wiring/connections are the same, the EVIC just needs to know where to pull info from. Reading on the GC sites this morning (slow day at work), it seems that for the TPMS, some came stock reading only 4 tires, and the 5th could be added via a reflash done by the dealer. I wonder if the dealer has the capability of upgrading the EVIC, even if they don't know that they do?

I'll have to see if I can get my Chrysler friend to pull a 2003 manual or schematic for me to discern what changed.

 

[Atrus]

By the way - does anyone know who manufactures these for Chrysler Group? I don't really feel like pulling mine back out to try and find a manufacturer logo.

 

[Corwyyn]

First dibs if you do replace it with a newer unit

 

[Corwyyn]

Marlon got me to thinking, so I just checked the FSMs for both '03 and '05. The '03 does take the temp signal from the BCM, and in the '05 it comes from the PCM (powertrain) module. I would think the engine control systems would have a temp sensor anyway, maybe they just decided to do away with the stand alone unit that was in the earlier models. Anyway, that's what I learned today

 

[Marlon_JB2]

OK, so my memory didn't fail me today.