A friend of mine has a MY2007 X150 and his touch screen display is blinking as per attached video. Any thoughts about what the remedy could be? The local dealer suggested a TSD replacement, but, to be honest, we're not entirely sure it's actually faulty, i.e. could be simply require a reprogramming session or a faulty cable?

Cheers

Andrew

 

Everyone will tell you to check your battery, regardless of age. Check resting voltage at the battery terminals. Should be a minimum of 12.6 volts. Alternatively take your ca to an auto parts store and have them load test it (it's free). If it's not the battery, then this ; I didn't look at your video You should upload to YouTube for viewing.

It's a classic symptom of a failing module in the MOST bus fiber optic ring. The flashing symptom is the faulty module attempting to reboot. The fiber optic ring is being interrupted, There are two stacks within the ring. Trunk stack and center stack. The center stack is the stack of modules under your touch screen. They include the touchscreen, the ICM which is a gateway between canbus and fiber optics (so they can speak to each other). That's the little black box on top of the CD player. Then there is the CD/radio Player. If you have premium audio, there is also the amplifier under the carpet in the passenger footwell.

In the trunk there are a stack of modules. Bluetooth module for you phone, The Navigation DVD module (maps) if you have satellite, that module, your iPod module. BT, satellite and Navigation are the usual suspects. You need a fiber optic bypass loop. Simply disconnect the fiber optic line from the module, pick one at a time, and connect the bypass loop to the fiber optic line. Turn on your car, if the problem stops, you found your offending module. If not, reconnect it and move on to the next one.

 

Whenever you have any kind of electrical problem, the first thing to do is to make sure that your battery is healthy and fully charged. That means at least 12.6 volts in the morning with the engine off. Convenience Mode is a misnomer, as It can quickly drain your battery if the engine isn't running. To me, that's an inconvenience.

If your car is not your daily driver, you should invest in a quality battery maintainer (not a trickle charger) to keep it fully charged. I recommend the CTEK brand, but there are others. Years ago I bought a Battery Tender Jr and it almost caused a fire in my garage.

A few important points:

There is an important difference between the 4.2L and 5.0L models. The 5.0L models came from the factory with a Battery Monitoring System module attached to the negative battery terminal. It's complicated, but simply put it controls how and when your battery is charged to maximize battery life. When that module is working properly, voltage fluctuations can make it appear to be wonky, but it's not. Never attach anything to that negative battery terminal; instead, use a chassis ground. Otherwise, your BMS module can be damaged and your battery won't be properly charged, which can result in a shorter battery life. 4.2L models don't have that BMS module. (My 2013 XJ 5.0LSC has the BMS module. Since I don't drive it daily, I keep it on my CTEK MUS4.3 using the alligator clips with no problems.)

See these threads for more information about the BMS models:
https://www.jaguarforums.com/forum/x...change-241034/

https://www.jaguarforums.com/forum/x...talled-277608/

Stuart

 

Thanks @Sean W for your observations. Despite the blinking (which seems too regular to be a backlight fault), all functionality of the TSD seems to be working, a/c, nav, audio, etc, etc. I guess that if there's a MOST ring cable fault, this shouldn't be the case?

 

Not really no. While it's possible the TSD is failing itself with the functions on it still working, the question is have you confirmed every module it working? BT telephone, Satellite radio if you have it, Amplifier (if you have premium sound) radio AND CD player and does Navigation actually work. You can unplug and bypass the BT module and Navigation module separately using a bypass loop and if the blinking stops, you prolly found your problem. The other module behind the trunk stack (Information and entertainment Control module) really controls the messages sent from the fiber optic loop to the can bus and back so if you have continuous sound on the CD player and the radio that's the least likely.

 

Fair enough @Sean W , valid point! Will get my hands on a MOST loop and test the all modules out. Thanks!