Questions & Answers

TPMS Light after EVO-ONE install; lots of Communication Lost codes

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Hi, so after my remote install, the TPMS light is on all the time.  I understand during remote start this is normal, but this is all the time.  I have checked all my tires, they are within normal range.  So I ran a code pull on all CANBUS systems, and the result was CURRENT/HISTORY lost communications codes on several modules, one being the TPMS system.  It is system code B1247, Main Body ECU Lost Communication... however there are several others too, a dozen or so, to other systems.  I thought perhaps they were historical from when I disconnected everything to connect the T harness, but I cleared them and all came back, after I tried clearing just the TPMS code unsuccessfully.

I attempted clearing the current/history lost communication code.  The light went out for about half a second, and it came back quickly.  Checked codes again, it was back.  Not sure if that screen shot is visible, all I can see is a placeholder symbol.  I will place a share link in my google drive to the code list.  VIN removed, but it is a 2018 Toyota Corolla H-Key using THAR-T18 (think the kit i bought was EVO-ONE-T18?, I'll reference and update, but it was the EVO-ONE kit containing the T18 harness)

I am presuming this is possibly a programming issue with the EVO-ONE module since the OBD2 port passes thru, but not sure.  This is my first experience with Fortin products and do not want to start messing randomly with settings I do not fully understand yet.  I've done remote starts before but this is my first Fortin system, switched because of the quality level; I do have a EVO-FLASH unit and have the ability to flash/reprogram everything myself, I have all tools and interfaces needed to make it work, thanks in advance.  Details are below:

2018 Toyota Corolla H-key, EVO-ONE, THAR-3 / THAR-18, RF442 installed, TPMS-hijack installed to allow OEM remote start (working OK since installed)

https://drive.google.com/file/d/1wVWxhNDwFs4chpdfGXHE7lqC3UKpKHwd/view?usp=sharing
asked Mar 17 in Toyota by Darrell Bunger (190 points)

1 Answer

0 votes
Hello,

Sounds to me like your tpms wire is open all the time. I'd put it back together and see if the light goes out, if it does I'd go over how you have cut and connected to that circuit.

Best regards.
answered Mar 18 by derek g (346,560 points)
I will check it.  I cut the harness wire identified as TPMS, soldered the wire in place on the connector side, then ran the return wire from the EVO unit back to the other side that came from the harness.  Maybe I got them backwards, will check... but it doesn't explain all the other lost comm codes along with TPMS.  I'll report back.

It can't be true loss of comm, or the car would be running awful because of the systems that are reporting loss of comm.
So I opened up the dash access into the driver side dash panel and checked the wires.  The goes into matches the goes into and the goes outa matches the goes outa as far as location, pin number, wire color, etc.  Solder joints are still solid. Pressed on the connector really hard to make sure it was fully seated in the TPU module, no snap or movement I was able to feel.  

Immediately after, that drive home there was no change.  Got in to go to work next day, light was off.  Still off today.  I suspect that clearing that history code, while it might have come back immediately, perhaps took some miles to fully clear itself.  I've now got a clean console and when I go home tonight, before I leave I'll run another code scan and see what it says now... I suspect it's gonna tell me that there's no longer a loss of connection history code for TPMS or the others that I cleared out.  I'll update if not... but I think that's all it was, a leftover from the install that didn't wanna let go.

This is probably the carry over code left behind from disconnecting that harness from the TPU Module that it plugs into. Car saw it unplugged, pegged no comms to every module I just unplugged, logged it and held onto it even tho it had comms after plugging back in, still a history of comm loss flag.  Wouldn't be the first time I saw a code truly clear only after taking a drive or two with significant mileage on them.
Hello,

Glad to hear!

Best regards.
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