MY2018 F-Type R.

Anything I can further try to resolve the code? Is it expected that a code is thrown when the module is reconnected & that the dealer would have to reset it?

I located a buzzing/rattle inside telematics unit, adding some insulation inside it around the circuit board metal plate and making sure the buzzing is gone which was very satisfying. I was careful not to damage or disturb anything.

I turned on the car WITHOUT the module plugged in and got the SOS System Not Available. Car would not start which I later learned is by design if SOS is disconnected.

I then plugged in the module connectors, turned on and got SOS Limited Functionality. I took a guess the module's small battery might have needed replacement and bought a new OEM (part LR089861) one since it was $17, however after replacing it and driving the code does not go away.

I tried reconnecting the main car battery as well as charging it with CTEK MXS 5.0 overnight.

I also tried an OBDLink MX+ reader but it didn't see any codes and clearing DTC didn't help, likely because this is an OEM DTC instead which I don't know of any personal use OBD reader that could see these codes.

 

Although the 'SOS Limited Functionality' error message appears for various TCM related faults, I've not been able to identify any DTC that is logged (iCarsoft using Jaguar interrogation mode).

The main 'SOS Limited Functionality' issues with TCM are:

1. Lack of signal for the built in SIM card to connect to Jaguar InControl services.
2. Discharged rechargeable lithium battery.
3. Disconnected centre speaker - yes really. MY2018 onwards use the centre dash speaker to provide inbound communcation from the InControl emergency services. The TCM has a detection routine to check continuity of centre speaker and will throw up error message if centre speaker not detected. Even if you have base or Meridian 380W sound system, you will also have a centre speaker exclusively for telematics.
4. Error with the TCM itself - unfortunately my case. Expensive out of warranty repair

Any work on TCM needs to be concluded with reset routine to establish communication with InControl services. See linked video from 6:30 onwards -->

 

Excellent video, thank you!

In my case I happen to be in the middle of upgrading all my speakers to the super premium meridian ones so the center speaker is not yet connected! Interestingly I get no audio from the center channel with the stock or new speakers even though I have the AUD4-16 / PREM 16 audio (Meridian Surround, Dolby etc) which should work. That's a topic for another thread.

I did plug the center speaker back in and the issue didn't go away even after trying the your hold down service key reset. I tried it a few times with and without engine on.
What worked was to additionally unplug the battery and so far the SOS light is gone. Now I had unplugged battery alone a few times prior so that alone was not enough.

So the secret combo is likely all 3 combined:
1) center speaker connected
2) service light reset hold
3) re-connect main car battery

I'll keep an eye and see if it resurfaces and how it reacts when I disconnect the center channel again for upgrades/debug.

Thank you sir.

 

I tried to replicate the issue and fix, so far unsuccessfully.

You are correct that unplugging the center speaker is enough to trigger the code.
However hold down to reset (fast blink until slow blink) doesn't resolve it currently.
Nor does reconnecting the main battery.

Maybe there's some additional timing/sequencing for the TCM (TCU?) reset.

 

I don't know of any further 'user' reset procedures for TCM. It could be that you have damaged the TCM when opening it up to address the buzzing issue, or that the buzzing issue was an indication of a failing TCM. You also mentioned that you did not get audio signal from centre speaker when DSP was set to surround, so centre speaker could be blown/damaged. Either way, I think you are now at the stage where dealer or independant specialist diagnostics may be needed to resolve the issue. Good luck and keep the forum updated.

 

The guy in the video isn't very bright if he didn't know the SOS button calls the emergency services - it's stated pretty clearly in the documentation. Always get to know your car before using it!

 

I confirmed that the speaker itself is working by connecting it to the door instead for testing. It just doesn’t play audio when in the center dash.

So that leaves the connector, connection or telematics unit. Will keep experimenting.

 

My light came back on after changing the battery and pushing the service button until slow flashes... About a month later it went off and has stayed off... Another thought might be the replaced battery was not charged sufficiently, and after some driving it has come up to the required voltage... These are rechargeable batteries and depending on how long they've been on the shelf they do tend to lose charge... I've read they don't charge when you charge the main battery, only while driving...

 

I got the limited SOS warning when my telematics battery got old. For my model year, it's a double battery pack, one of which is rechargeable. It took a little driving to get the new one charged up but it's been fine since.

As for the center speaker, I would not expect it to be able to trigger an SOS system fault, but that is clearly the case. I do recall documentation saying that not all audio modes use it, although I haven't read through the audio system manual since 2015.

 

In my case I just installed a brand new TCU battery so it can't be that either. I did charge up the car battery overnight as well as go for a long drive.

 

Actually, it could be that. As I noted, my new one it took a little charging up before the alert went away. Maybe a few 20 minute drives? I can't recall. I probably commented on the thread about "SOS Limited Functionality" where we discussed the batteries in more detail. It might also be that you have a different battery. There were a couple of choices when I needed one and I had to match the VIN.

As far as I know, the main battery has nothing to do with the SOS warning, although conventional wisdom here is that a low battery can cause just about any problem imaginable.