After about 5 miles of driving my '06 Super V8 this afternoon, I noticed the red light on at the top of the temperature gauge but the needle on the gauge was at the bottom as if the ignition was off or the gauge wasn't connected.
The electric fan was running until I shut the engine off. I didn't remove the reservoir cap but the engine seemed to be at normal temperature. Nothing was displayed on the message centre.
My guess would be a faulty temperature sending unit has tripped the red light. I didn't find anything in the owners manual about the light and wasn't able to find an account of a similar situation here.

Anyone else experience anything like this?

Updated: After letting it sit for about 30 mins I removed the cap and there is plenty of coolant in the tank. If it's low it would be by about a cup.

 

Does sound like the sensor (or its wiring etc).

Repair issues are commonly not in the handbook (but would be in the workshop manual).

 

I had this exact same thing happen once. The next day when I went to pull codes the gauge was working normally again. I'd agree, this warning is probably that the ECM has lost its coolant temp signal.

 

Thanks for the replies . I only mentioned the owners manual because I couldn't find anything about the red light on the temp gauge there. It only mentions the needle on the gauge. I hadn't even noticed there was a light until it came on.
I'll run a scan but wouldn't be surprised if this sorts itself out, at least temporarily.

 

Here's when I posted this happening to me (with photo) https://www.jaguarforums.com/forum/x...failed-165656/ You're correct, the owner's manual says nothing about the indicator.

 

Got in it this evening and and it was doing the same thing. Made a stop and when I got back in and started it, still no change. Got back on the road and glanced at it after a mile and all is back to normal and has been since.

Just one of those things.

 

Hi
I bought a great little OBD device that makes my life great - going to drill a hole in my ashtray to install permanently. Should be under $36, such as
[url=https://www.amazon.com/AUTOOL-Multi-Function-Water-Temp-Malfunction-Test-Automotive/dp/B07L8RPLCG/ref=asc_df_B07L8RPLCG/?tag=hyprod-20&linkCode=df0&hvadid=312280085431&hvpos=1o4&hvne tw=g&hvrand=15670769638953492171&hvpone=&hvptwo=&h vqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1013509 &hvtargid=pla-632688059030&psc=1]

Amazon

Amazon

I now take it from car to car as they all seem to have idiot light-fake gauges.

really helped me make sure I purged all my air after my last coolant flush

 

I am dealing with the same problem right now and I cannot seem to find a solution. I’ve tried two different coolant temperature sensors including OEM. Did battery hard resets. Drove around the block to get up to full operating temp.
Nothing changes! It still shows the red warning light and runs the fan at high as soon as I start it.

 

Have you tried a vacuum coolant test/recharging kit?

The Range Rover L320 5.0 l V8 is still dodgy, even-with.

But the XJ8-L's 4.2 has quit trying to create coolant-fail stealth time-bombs.