My car issue

[TheExactPlayer]

You have a parasitic drain. I had this type of problem on my Range Rover (same system). Main dealer said "nothing wrong, drive it more". Eventually went to an Auto electrician who found it but it took three days. Not as expensive as it sounds as they tried something, had to let the car go to sleep, then check, so I was not paying for the time the car was "sleeping". Main dealers can not diagnose anything that does not show a fault code. Get yourself a good Auto electrician

Due to the car being under warranty I have to let them fix this issue. Why should I be paying £1200 per year and them having to take the car somewhere else because they're incompetent?

[Tel]

@TheExactPlayer - Have you removed and reconnected the +ve?

Hi,

Yes, this has been done already.


The car was in Jaguar for three days and I was told the problem has been fixed by changing one of the motors.

Drove home, then next morning started the car and the same message appear on the dash. It seems they really don't have a clue what's going on.

I was told to bring the car back to them again! Because the car is still under the extended warranty I really don't want to take it somewhere else for a fix. They (Jaguar) should be able to resolve this issue for me without me paying for it.

There have been reports of these motors 'going', and this first manifests itself by pooping fuses.
It's caused by water not draining away from that area - I sincerely hope you don't have that issue.

[TheExactPlayer]

Update!!

Jaguar came back with the following. They want to charge me £1200 to replace the cable due to the corrosion it wouldn't be covered under warranty.

"Investigate the roof not latched warning light is on, found fault codes for battery voltage below threshold, communication between roof modules, roof switch, tested battery and this is ok, found battery voltage is low when vehicle running under load, workshop manual recommended updating the gateway and body modules, updated but still faulting, wiring checks found loss of voltage at the front power junction due to corrosion, cleaned and battery voltage ok, if fault returns recommend new cable"

I just don't believe this is the cause of the problem. Even without running the engine, and with a fully charged battery, the battery voltage is still low. How will replacing the cable from the alternator to the battery make any difference?

[Tel]

Because the corrosion at the jbox in the wheel arch is the most stupid design ever and fills with crud/salt etc and has dissimilar metals... Et voila, accelerated corrosion.
Any joint that does not conduct electricity well due to corrosion will restrict the amount of current that can pass through it, as I have mentioned in pervious posts, these motors need a lot of ooomph.
The battery voltage may show up on a charger as OK, but there is no way of measuring the amount of current (pushing power) it can supply until you demand current, in this case the roof motors.

So whilst you may not belive it, it's a known fault that has been highlighted in the forums before along with great pictures.

Have a look at the jbox and check to see if it shows signs of being cleaned perhaps.

[Deleted User 1715]

Because the corrosion at the jbox in the wheel arch is the most stupid design ever and fills with crud/salt etc and has dissimilar metals... Et voila, accelerated corrosion.
Any joint that does not conduct electricity well due to corrosion will restrict the amount of current that can pass through it, as I have mentioned in pervious posts, these motors need a lot of ooomph.
The battery voltage may show up on a charger as OK, but there is no way of measuring the amount of current (pushing power) it can supply until you demand current, in this case the roof motors.

So whilst you may not belive it, it's a known fault that has been highlighted in the forums before along with great pictures.

Have a look at the jbox and check to see if it shows signs of being cleaned perhaps.

That junction box is such a known weak point I think Jaguar are being very cheeky asking to be paid to rectify it, wouldn’t surprise me if they already had a kit available to dealers to rectify it. I will be checking mine annually and applying anti-corrosion products.

[TheExactPlayer]

Because the corrosion at the jbox in the wheel arch is the most stupid design ever and fills with crud/salt etc and has dissimilar metals... Et voila, accelerated corrosion.
Any joint that does not conduct electricity well due to corrosion will restrict the amount of current that can pass through it, as I have mentioned in pervious posts, these motors need a lot of ooomph.
The battery voltage may show up on a charger as OK, but there is no way of measuring the amount of current (pushing power) it can supply until you demand current, in this case the roof motors.

So whilst you may not belive it, it's a known fault that has been highlighted in the forums before along with great pictures.

Have a look at the jbox and check to see if it shows signs of being cleaned perhaps.

Hi,

They sent me a video after cleaning it and it looked OK from what I saw. So, the battery is fully charged and the car hasn't been started for 2 days and the same error is still appearing on the dash the next time the car is started. How is that still a jbox issue from the alternator cable to the battery? I wouldn't mind if this only happened after driving the car, but it also happens after a full charge and the car not used at all.

[Tel]

I assume the dash board error is... Low voltage pls start?

Without diagnostic and access to your car;
Sounds like the jbox problem may have fried the alternator at a guess if it's still not charging?

Or the battery has a duff cell in it.

Or could need a simple reboot to clear the errors from the modules...

[TheExactPlayer]

I assume the dash board error is... Low voltage pls start?

Without diagnostic and access to your car;
Sounds like the jbox problem may have fried the alternator at a guess if it's still not charging?

Or the battery has a duff cell in it.

Or could need a simple reboot to clear the errors from the modules...

No, the error I'm getting is the same "Roof not Latched" when starting the car. If the car has been charged using my Ctek charger, and then unplug the ctek charger. Without starting the car for 1-2 days, why is the error still appearing? I thought the alternator is only there to charge the battery when the car is running? Unless something else is draining the battery while at standstill.

[scm]

Measure the voltage when the engine's running - should be over 14V. I have a cheap little meter that plugs into the accessory socket to quickly check. Though I find when the engine's off the meter usually shows only 12.2V which is low for a battery, so I'm not convinced the socket is directly on the battery +ve line. Other theories/explanations welcome.

[TheExactPlayer]

Measure the voltage when the engine's running - should be over 14V. I have a cheap little meter that plugs into the accessory socket to quickly check. Though I find when the engine's off the meter usually shows only 12.2V which is low for a battery, so I'm not convinced the socket is directly on the battery +ve line. Other theories/explanations welcome.

This is the message from Jaguar. They've already done the voltage test.

"Investigate the roof not latched warning light is on, found fault codes for battery voltage below threshold, communication between roof modules, roof switch, tested battery and this is ok, found battery voltage is low when vehicle running under load, workshop manual recommended updating the gateway and body modules, updated but still faulting, wiring checks found loss of voltage at the front power junction due to corrosion, cleaned and battery voltage ok, if fault returns recommend new cable"