I have an 2003 XK8 4.2 V8. The temperature gauge won’t work despite my having changed the temp sensor, I bought a new coolant bottle. The car doesn’t overheat. I’ve stopped driving the car because I’m worried I might damage the engine should it overheat. I tried using an bluetooth OBD2 to check the car temperature gauge… Using a mobile phone app Torque… But the message says no data…does that mean there’s no communication between ECU and the temp gauge?
Please help. I miss driving this cat
As I recall, temp gauge doesn’t actually measure temp. gauge just sits in center of reading and only warning from gauge comes when it’s too late or from idiot light in cluster. Some one a while back came up with a couple kits to make temp gauge and “dummy” oil pressure gauge actually do something.
and https://www.jaguarforum.com/showthread.php?t=56455
NO affiliation with either of the links I provided
If I was investigating this fault, as you have already changed the ECT my next step would be to monitor the voltage from the ECT where it provides an input to the ECM. According to the 2003 Electrical Guide this is connector EM80 pin 70 (should be a blue wire with a yellow tracer). I would expect to see the voltage there vary between a nominal 0 to 5v as the coolant warms up. It will be a bit difficult to get at.
Eric
Shropshire UK