RoverGauge sudden drastic main voltage drop ?

[blaze_away]

blitzracing said:

What gets me is the temperature readings are completely steady in the logs when it goes wrong , so I cant see how a shorted temp sensor would cause the fault. Time will tell.

Yep thats exactly what I thought. I went back to the logfiles and water temp in RG is completely normal as is fuel temp

[blitzracing]

Had a dig around the circuit diagram- the temps sensor has a voltage on a sense wire from the ECU, and the other side has a common ground for coolant, fuel, airflow & throttle-position sensors. I guess its possible it pulled the ECU "ground " up if it shorted out, as its not chassis ground and may not be connected directly internally as such, and that would mess with the readings- the AFM certainly drops to zero near the time it all dies, and pulling a ground up would reduce the voltage difference to the 12v supply rail but its a bit of a long shot at best.

Edited by blitzracing on Wednesday 21st October 21:11

[Penelope Stopit]

blaze_away said:

Posted over on fb

No wonder the data looked odd.

quote
[i]
Simon Harry Firth
I gave in and sent it to my mechanic. He’s found the issue. It was a couple of frayed wires to the temp sensor. As she was heating up it caused them to short and send the temp sensor crazy. Repaired the wires and a new sensor. Problem seems to be solved. Thanks everyone for all the help. Now trying to get some time in her before I put her away for winter.
[/i]
Unquote

Makes no sense

Couldn't possibly cause a drop in ECU Main relay supply voltage, main ECU earth/earths will be used to measure voltage