P0117 water temperature error. I tried changing the sensor but it didn't work. It's probably sensor #1 near the driver's seat. I looked at the wiring but couldn't find anything that looked like it. The wiring continued to the rear of the body, but I couldn't follow it any further. Is there a wiring diagram that shows where it leads? The water temperature was about 140 degrees, so I think the resistance is high.

 

140 in C or F?

Did you look at the shop manual on this PINNED topic? Don't start at the beginning, some of the early links are no longer valid. I'm sure someone will provide a direct link to it...

https://www.jaguarforums.com/forum/f...mation-101906/

 

Here’s a wire harness and connector cross reference…
https://www.dropbox.com/scl/fi/a1wz9...=cz0lb1s7&dl=0

Here’s the workshop manual with wiring…
https://www.dropbox.com/scl/fi/o6d1x...=2ifycxho&dl=0

 

Thank you everyone. I removed the sensor and checked the continuity from the connector to the ECU connector, and one side had continuity with ECU connector number 54. The other side had continuity with the body ground. So I'm thinking it's an internal ECU problem, and I'm currently taking the ECU out and opening it up.

 

Don't touch the ecu, that rarely has problems, most likely your thermostat

 

However, when I monitored the sensor temperature, it was 140 ℃. There is a short circuit somewhere. I removed the connector from the ECU and measured the continuity of the wiring with the sensor removed. There was no short circuit in the wiring. For some reason, terminal 54 on the ECU side (the positive side of the sensor terminal) was connected to the ground. I think it's a problem with the ECU. I've already opened it up and looked, but I don't know.

 

The way the Ecu works is that it interpret information from modules and controls thr signals if there's a breach it won't send the signal to the corresponding instrument eg fire a fuel injector or so,if a sensor is faulty it won't engage it

 

Would it work if I bought a used ECU with a key and key cylinder and replaced it?

 

are you in Celsius or Fahrenheit also there are 2 sensors ,one on the rear crossover pipe and one on the thermastat

 

The temperature is in Celsius. The sensor is the one near the driver's side. I'm not sure what to do as it's likely an ECM problem. At worst, I'll get rid of the engine check light on the meter.

 

Which side does the driver sit?

 

It's right.

 

Since there's nothing I can do about it, I'll just have to remove the bulb from the meter. Will the engine temperature sensor #1 be limited in function due to a high temperature?

 

Forget the ECU as posted up thread by Dennis. That's not your problem.
Have you checked for codes?
.
.
.

 

I finally solved it. The temperature sensor connector was plugged into another connector nearby. I don't know which idiot dealer did it, but I noticed it by looking at the wiring color. Thank you very much.