Intermittent codes C1611, C1643, B1493, P0335

Thank you for the response and some positive outlook that there is hope. I am rusty with electrical diagram but have basic car knowledge. This is perfect timing. I am going to a friend's house today that has a better understanding. I couldn't find electrical diagrams anywhere online for my vehicle and was trying to get something from the dealer, but no luck. Any other suggestions/test if the connections are within spec, or would it most likely be the ECM? Any recommendations for the company that sells and reprograms if I need a new one?
Have a good day.

Update:

Approximately 550 miles from last code/ problem
Took car for test drive after brake job went over some speed bumps and basic driving for about 10 mins. Went over a speed bump came to a stop sign turned left went down the block approaching stop sign and the engine dies. Turn the car off. I went to start the car cranked a few times then started. Engine light and traction light on, no rpms on gauge and was in limp mode for about  a block.
Codes: p0335 local can bus off.
C1611 active cooling fan relay.
Checked fuses, all good.
Switched cooling fan relay with window relay and back turned A/C on and fan kicked in both times after a few minute.
28 March 09
Fiancé driving car for about 5 miles round trip. Go to store, restart the car after shopping and turns out of parking lot when the traction light appears, she pulls vehicle back in lot, turns car off and then restarts car light goes off.

March 10
Drive is 24 miles each way.
Driving on expressway as I’m accelerating, changing lanes, traction light comes on, goes into limped for a mode 5-10 secs , rpm gauge drops to 0 and stays at 0 for the remainder of drive. Car allows me to proceed and functions normal the remainder of drive. Got to work, turned car off then back on light goes off. Drive home was normal with no problems
At home try to replicate the problem with a test drive for about 30 minutes. Car drives normal. No lights / codes are below.

Codes c1643 dtc -comm time out yaw rate and g sensor.
C1611 dtc-lost communication with ECM

March 11
Cleaned throttle body plate with tb on vehicle with MAF cleaner on rag, did move throttle with hand. Started car to go to work check engine light appears, throws code but drives normal to work. Tried a relearn procedure. Started car kept rpms at about 3k rpms for 5 mins for a relearn. Turned car off. No light . No problem driving home from work which is 25 miles. Code that was present.

P0106 †dtc-map /barometric pressure circuit range performance.
I cleared code and car drives fine until March 15 after about 150 miles

March 15
traction light appears while driving after making a hard turn but didn’t hit nothing. Only driving about 1/4 mile. Throws code b-1493 ocs communication error. Turned car off then restarted car. It was a hard start traction light stayed on returned home after a 1/4 mile. Turn car off wait a min stared car light is off. Drives normal again. Test drive for another 10 mins. Car is normal

Code b-1493 ocs communication error

Although it seemed live data was slow/lagging in my scan tool but it is only a 200 dollar tool. Example : car went from 800 rpm to 2500 by time tool caught up. I was in idle at stop light again.
March 16
Driving 3 miles was waiting at stop light to change, proceed from stop light, car jerks check engine came on a quick second then disappeared but traction light stayed on. Goes into limp mode, rpm gauge not drops to 0 and remains there the whole ride home. Rough idle for the first few mins when at stop lights. Car then begins to drive normal come to a stop light, proceed from stop light car goes back into limp mode for about 4 blocks then goes back to normal. Get home turn car off. Restart car is normal drive for about 30 mins no lights. Codes below appeared
B1493 ocs communication error, c1611 active cooling fan relay
Drove car to dealer about half hour after test drive which is approx. 8 miles no problem

. After keeping car for two days. Dealer said they only spent a half hour with it and was no help and basically related the same info that you can pull up on google when researching the c1611 code about poetically being three problems and said its either the abs system module, which is obsolete now, the computer ecm which he cant get or problem in wiring harness. Basically no help at all asked dealer if I got a reman ecm or abs can they reprogram/relearn. He said they cant/ don’t recommend because it has a vin already burned in it and the car wont run right. But gave me options to buy a new hyundai
Any suggestions? Thanks in advance
Also,
I did change the crankshaft position sensor and the driver rear wheel speed sensor after code c1260, c1207, c1611 back in August 2020.
22
Conducted voltage test with outbreak box from pin 4, 5, to 16. Read normal 12.3 volts
Conducted ohm test while car was off and asleep between can low and high 61.2 ohms
Conducted voltage test from ground to high can 2.7 v, low was 2.2 and 2.3 v
Tested connector for crank sensor with key on ignition off ground lead on ground battery post/ 12.2 volts, 4.93 volts for signal and 0.1 for ground is this the same test you provided me with? My next step is the PCM connectors

Took for test drive for about 10 mins no problem. However, sitting in front of house at idle for a few mins all of sudden rpms went high then back to normal. Let run for a few mins. Raising idle to about 2400 rpms and back down. No problems front reading lights are flickering, do you have any diagram for that?
Should I still disconnect PCM and test for 1 ohm between connectors the ECM and PCM is the one located by battery box correct. (Pic below)
Any other suggestions?
Thanks, in advance.

I don't want to damage anything and am rusty with electrical. When testing PCM and connector, do I have to unplug the battery or follow any extra steps before unplugging PCM for the ohms test. What other test can I perform to diagnose or rule out PCM since I performed your other suggested test?

What's the other module on my vehicle that has the resistor? ABS?
Also
The only lights flickering were the reading lights. I changed the lights back from led to right bulbs for the reading lights and is not flickering. I just didn't know if that was tied into my problem.
Thanks again for all your help.

Update:

Good afternoon.

Do you still recommend testing the connectors at ECM for resistance if I used the breakout box to test for volts and ohms at the dlc. Do you by chance have the wiring diagram for the can line and what other module has the resistor?

If I disconnect my battery. How long do I have to wait after disconnecting the battery? Also, if I disconnect the battery, won't I lose the data stored on ECM? I may be taking it to a shop if I can't figure it out, but that's my last option.
The car now will run fine for a period of time and has shut off at idle in my garage 10 minutes after test driving. Starts right back up. No check engine or trouble lights. Just code c 1611. Cooling fan relay.

Tested cooling fan relays high and low, both relays work. Turned A/C on after a few minutes. The low cooling fan relay clicked, and the fan was on. Switched high and low relays, performed the same test, and it worked.

C 1611, cooling fan relay.

Thanks again.

Thanks for the diagrams and quick response. I tested with key on the crank sensor harness connector from battery ground and had 4.93 v at signal, .01 at ground and 12.2 v at hot wire. I also tested resistance from battery ground and 2 of the chassis grounds near fuse box by air box both.01.
I will perform the same test from chassis ground tomorrow.

Also, why would the c 1611 say it's a cooling fan relay? When communication is lost, does it throw the code to with any sensor on that connection? First it was the steering angle sensor, then lost communication with ECM. Now cooling fan relay.

Thanks

Good morning,

Update: I took my car to a mechanic on April 9th since my time was limited with work and he told me he would look at it, well he got swamped and for whatever reason kept pushing my car off and after calling several times I finally picked my car up on the 18th and took it to a another shop that had high reviews with a good reputation and is said to have high tech engine diagnostic tools with reprogram and etc. They looked at my car and fixed it on the same day. It was my crank sensor that was failing. I did have the OEM one on the passenger seat which I should have installed before taking it in but decided to let them see all the problems so they can diagnosis it with the symptoms I was encountering. Also, they had said the stalling was also due to my intake manifold runner solenoid which I thought was outside the manifold case, but they said they also had to take off the manifold plenum as well to fix something else. The bottom line is my car is running great and I wanted to say thank you for your time and info. I did learn and/or get a refresher on some engine diagnostic especially with the BUS CAN line.
I asked them why my scanner was related to the c1611. It was saying it was the cooling fan relay and they related the same thing you said that it had nothing to do with the cooling fan and it was giving a generic code because it was a less expensive scanner. I thought it was decent but guess not.
Thanks again.
Have a great day.