Hi RoverJoe,

I’m reaching out because I’ve seen your expertise with JLR systems. I’m struggling with a TCU-related 'No Crank' issue on my Jaguar XE.

The Situation:

• Errors: 'SOS Limited' and 'SOS Unavailable' (intermittent, but now persistent).
  
• Hardware: I found oxidation on the TCU board and a leaky/loose shark fin antenna.
  
• Battery: The backup battery was imbalanced (one cell at 2.5V, the other at 3.7V). I'm currently пытаюсь (trying to) rebalance/charge it on a bench.
  
• Goal: I don't care about the Telematics features. I want to either fix the communication to restore cranking or, preferably, code the TCU out (CCF delete) for peace of mind.
  

Since I'm in France, do you think rebalancing the battery will clear the 'No Start' if the PCB is cleaned? Or is a CCF edit the only reliable permanent fix?

Any advice or contact for remote coding would be greatly appreciated. Thanks!

 

If you can clean it and get the communications back with the module, it would start. The backup battery and other faults won't stop it from starting. If you cannot get the module to be back online and communicating properly to allow the start signals, then yes you would need to have it coded out.

 

Thanks for the clarification, RoverJoe. Since my TCU communication is unstable and requires a forced reset to respond, I’ve decided to go ahead with the deactivation (CCF delete) to ensure reliability.

Could you (or anyone in the group) guide me on the specific steps for this?

1. Software: Should I use JLR SDD or Pathfinder for a 2.0D XE?
   
2. Parameters: Which specific fields in the CCF do I need to change? Is it just 'Telematics' to 'None/Not Fitted', or are there other dependencies (like the VEMS or cellular data fields)?
   
3. Hardware: Is a standard ENET cable enough, or do I absolutely need a J2534 passthru (like a Mongoose) to write the CCF?
   

If anyone offers remote coding services for this, please PM me with the pricing. I have a laptop and a stable power supply ready.

 

The CCF mods are above my level, I have only flashed the exisiting files via SDD, not modified them myself. There are others in this thread who seem to have done that before though, i'm sure they can help you.
Which diagnostic software just depends on the car, jags up to 2017 were SDD, after were pathfinder, the change was the addition of an ethernet line for diagnostics. I don't know on the other questions.

 

Hi, I saw your comments on the post about deactivating the Telematics system. I told the technician who works on my car about it, and he's unsure how to do it. Do you have the procedure for deactivating it? I would really appreciate it because they've already replaced the Telematics system on my car about three times, but if it can be deactivated, that would be much better.

 

I too have the TCU2 failure in my Jag. The issue started about 5 months ago when I had my battery replaced. The shop didn't bother to inspect the terminal clamp that was terribly worn and loose. Then I had intermittent starts. To compound things, I had a small vacuum leak in the rubber boot at the MAF sensor, which I fixed. Yet my car was still showing 25% STFT and high LTFT, yet the lean condition codes disappeared. Then the starter failed and I got that replaced.

However, I kept having an intermittent starting issue. I thought the key fob battery was going dead so I replaced it. The starting issue continued. I took it to a local shop that has worked on my car for the last 4 years. I trust them. They determined that the TCU2 was intermittantly failing, not dead stick. They checked the lithium backup battery and it was 4 volts. There was no water damage to the module. The SOS light comes on after a battery disconnection because it was the only way I could get the Jag to start. That still seems to be the case. And since you no longer can buy a TCU2 from Jaguar because ACTIA isn't making them anymore, I'm searching for a workaround. I called a local Jag dealership and they want $7000 to do an OEM bypass! Hell no!

I would appreciate any direction or advice on this.

 

Try a different dealer, they should be able to code it out for you for an hour or two of labor, it's not that involved. With the current lack of remote assist software it might require a field engineering visit, but that's always possible.

 

First of all, thank you for replying! I just picked up the Jag from my local shop, getting diagnostics. No parasitic battery drain, no U codes. The tech said he went out this morning and it started right up. So far for me, it's started 3 times. But he showed me a power probe work around just in case. What I'm hoping for is the TCU is just actuing up because of voltage instability. Long story! But the cool thing is the backup battery in the TCU is ok, no water damage to the TCU. Just a bunch of network BS!

 

Update: For all of you with XF/XE and probably even LR, when I picked up my Jag yesterday, the tech showed me a trick/workaround. Use a Power Probe and turn on ACC then find the starter 5 amp fuze by the passenger side in engine bay. You'll have to look at a schematic for your particular car. After you connect the probe to power, touch the probe on the 5 amp fuze and hit the probe's switch. The car will start! No disconnecting your battery!

 

That sounds like your car has a bad wiring issue supplying power to the TCU, that will NOT save you if the TCU goes off network and doesn't send the start allow signal.

 

Hi, I'm Gerard, I'm Italian, I have a 2016 XE S. The SOS light is not available, the engine won't start, it's at the mechanic, we've checked all the relays and fuses, everything is fine. We first replaced the backup battery, then removed the TCU, and there was some rust, probably due to leaks. We cleaned the pins, but unfortunately, it's not detected by the diagnostics. What should I do? These are my telephone and email contacts. 0039 366400719 info@pantorronegarofalo.it
I'm in serious trouble. Thank you.

 

I apologize to everyone on this forum, haven't been on here for a while, and I wasn't aware some members need help. Another member on here emailed me about this thread.
Anyone needs help please support this forum, that way you can send private messages too.
hope this is OK with Administrators, if you cant message me here contact me at remotediagjlr@gmail.com

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