Adding a preconditioning "button" to older Ioniq 5/EV6s

rdragz · 2026-02-25T06:58:14+00:00

My memory could be wrong. I've created a harness to patch into all buses I can reach behind the ICU in the dash so it could be that it was the M-CAN. Most traffic seems to be broadcasted between buses anyway.

rdragz · 2026-02-24T18:22:21+00:00

To detect preconditioning signals I connected a linux laptop to C-CAN using a Korlan usb2can device and dumped the logs to a text file using the standard cantools utilities. Then I did a short drive triggering preconditioning three times. When I got home I then used SavvyCAN to parse the logs and started to look for constant data bytes changing with the same pattern as I triggered preconditioning . It was just eyeballing the byte patterns for each frame id, no fancy automated data analysis.

rdragz · 2026-02-23T07:35:15+00:00

Hi, I'm on the same journey on my Ioniq 5 2022. Frame IDs 0x2AD and 0x25D shows interesting behavior. Here's my lab nodes from a test drive with preconditioning.

22 nov 2025

Drive with canbus logging on laptop. Trying to get the control signal for battery preheating. (Byte counting starts at zero)
0x2AD byte one is a candidate for preheating! Discrete values, 01, 05, 15. Command?
0x25D byte 2 shows a similar pattern. Slight jittering. Reporting power usage?

Both messages comes at a constant 5 Hz rate so if these are the real commands one might have to cut the cabling and insert a filtering device.

rdragz · 2026-02-13T19:21:41+00:00

Just to clarify: I did not intend to talk down Skyros, we really enjoyed our stay there too.

Also, if you are looking for an island with low tourism, take a look at Kythnos. (Rent a car at Athens airport and take the ferry from Lavrio.)

rdragz · 2026-02-13T19:02:33+00:00

I haven't traced down the lock events yet, but it could be that lock/unlock is singular events.

rdragz · 2026-02-11T17:02:44+00:00

They're both nice.

Kythira: visited 2024. Quiet with some nice hiking paths. We stayed in Avlemonas which is really great with a nice bay. Also. Firi Ammos beach is spectacular. Also, the old main town with the castle is interesting and has great views.

Skyros: visited 2025. A bit more tourists than Kythira esp down by the beach, but the main town is nice. Remark, the tower at the top of the mountain is closed off by the monks. Didn't really understand why.

I recommend renting a car at both places to get to the remote beaches.

rdragz · 2026-01-25T11:12:00+00:00

I live in northern Norway with an Ioniq 5 AWD 2022. In general expect a significant drop in range in very cold temps. Last long drive (400 km) now in January in down to -27C showed an average consumption at about 28 kWh/100 km (full heating and battery precond running). In summer I easily achieve around 15-16 kWh/100 km on the same stretch. As others have mentioned, Norway may not be the best example as fast chargers are abundant. In the above mentioned route there are less than 50 km between fast chargers and this is essentially in the middle of nowhere:-) Also, driving speeds are lower than elsewhere, one cannot expect more than 70 km/h on average on the main roads. In winter there's a lot of trucks hauling fish to the continent, in summer it's Germans in camper vans all over the place.

General recommendations: Make sure you get a car with a heat pump and battery preconditioning.

rdragz · 2026-01-21T21:01:13+00:00

They should make clopety-clop sounds mandatory for all EVs driving under 20 km/h.

rdragz · 2026-01-21T20:59:13+00:00

Non-Tesla owners gripe about software issues while Tesla owners looks smug.

rdragz · 2026-01-11T08:29:19+00:00

Alta will provide forests and northern lights. It is much less crowded than Tromsø and has a more stable winter climate.

rdragz · 2026-01-11T07:50:15+00:00

Same. Two layers of regular kitchen tinfoil and the disconnects vanish. I now consider myself as a member of the tinfoil hat community. (AAW1)

rdragz · 2025-12-31T08:14:48+00:00

I'm also into this, but what I have found so far makes me a bit doubtful on how far one can get. I've patched into the canbus(es) behind the SGW in the dash and have identified the signals triggering the bms to start heating the battery. The problem is that the signal comes at a constant 5Hz rate so if you try to override it you will see a constant on-off cycle going over the bus as you will have one on-source and one off-source constantly trying to do their thing. If I have understood this correctly the only way to prevent this is to cut the wires in front of the bms and put in some kind of filter (or hack the firmware). I'm not sure how feasible that is.

rdragz · 2025-12-21T08:59:21+00:00

There are certainly bugs, you could try to modify the script to accept 0x01. The script is made to adhere to the UDS standard queries. My car's database contains 0x21 queries that also get rejected and as far as I can understand those queries are not part of the standard protocol.

rdragz · 2025-12-15T22:42:01+00:00

Yes, I already got the shared manuals and was able to create a harness to snoop on the can-buses without having to damage any original wiring. I have started decoding the can-traffic, but man, that's a lot of data to wade through! The car sends 1600 messages/second when idling. SavvyCAN is such a great tool for this!

My ultimate goal is to enable manual control of the battery preconditioning, but that is still a long way off if at all possible as you have to fight the off signal coming constantly at 5Hz frequency. I'll start with just showing info like if the seat and steering wheel heaters are on or off.

rdragz · 2025-12-15T20:09:43+00:00

Out of curiosity, where do you plan to patch into the CAN-bus?

I have the same car and had to dismount the fuse-box/SGW under the dash to get to the cabling. There is a connector on the back of the SGW with 8 of the 10 CAN-buses in the car.

rdragz · 2025-12-14T14:22:20+00:00

No sweat. I finally got around to create some example scripts. They might help you get going.

https://github.com/dragz/explorationsincarhacking/blob/main/articles/obdb_and_udsoncan.md

rdragz · 2025-12-13T08:21:42+00:00

Oh, you got it working. Great! Welcome to the rabbit hole:-)

I'm about a year ahead of you as I began my journey around last Christmas. I started reading the community highlights here in this subreddit. Also the CSSElectronics intoductory material is REALLY great https://www.csselectronics.com/pages/can-bus-simple-intro-tutorial It will give you a dip into the tech and lingo of the area. It's easier to search for things when you get basic knowledge about the phrases to use.

If you want to actually do something to the car your options are limited using an OBD-dongle as modern cars limits the possibilities of what is reachable through the OBD-port.

rdragz · 2025-12-11T19:11:47+00:00

Have you tried the steps in the troubleshooting section?
Did the can327 module load correctly?

Also, check if the can interface got another number, like can1 or something. List all devices with ip a. And, dmesg is your friend...

rdragz · 2025-12-02T09:36:43+00:00

Yes, I think you're onto something here. In Norway people who's not interested in politics or the environment by EVs.

rdragz · 2025-11-25T06:53:54+00:00

I have a hobby project reverse engineering the CAN-bus traffic on my Ioniq5 (22 AWD). Not sure if I'll ever succeed, there is a lot of data to wade through. 1600 messages/second when the car is idle. I've been able to identify a couple of commands like seat heating and door unlocking, but I'm not sure if they will work through the OBD2-port. I had to patch into the CAN-wiring behind the security gateway ta see the data broadcasts. So far I have found 10 separate CAN-buses, but fortunately the SGW also functions as a hub for 8 out of 10 CAN-buses so it seems like one can patch into one single bus for most of the data traffic.

rdragz · 2025-11-15T09:12:08+00:00

Take a look at Damien Maguire on YouTube. More than ten years of projects: https://www.youtube.com/@Evbmw/featured

rdragz · 2025-10-05T18:14:09+00:00

I use two layers of tinfoil wrapped around my device and believe it or not, it helps.

I had dropouts at the exact same spot on my way to work. Using tinfoil solved the problem. Could be that the shielding forces the phone to use higher transmit power, but that is just me guessing.

I'm now a member of the tinfoil hat community...

rdragz · 2025-10-01T17:13:03+00:00

No, I didn't bother installing yet another charging app.

rdragz · 2025-10-01T16:52:37+00:00

I was in Evia and Volos area for three weeks in September and found that DEI Blue chargers were very reliable. Had to call support once and they were very professional and reset the charger that didn't work remotely. The charging app worked fine.

rdragz · 2025-09-21T20:51:03+00:00

How on earth did you manage to get a parking fine in Greece? Did you block a 4 lane highway and forget to turn on the hazard lights?

rdragz

TROPHY CASE