I take it you've measured battery voltage with a multimeter and its stable at 14v when ecu showing 24v? the temperature reading could be down to a slight short in the wiring or sensor, 120degrees would probably be what you see with a dead short. are both blocks showing the same with just ignition on and engine not running?
both blocks showing the same when engine is running when it is not running it wil stay on 12.2 V and the temp sensor also I had the voltage meter on it and this stays on 14 V it doesn't move like the block does Also put my Ohm meter between the temp sensor it also stays the same when the block says 120 Degrees
very strange, I'm leaning towards an ECU fault on that one, cant see how any kind of wiring fault could make voltage jump up to 24v...
Might as well subscribe to this thread while trying to get my 10 posts. Looking forward to getting the lbl file to facilitate diagnostics.
Getting similar issues with my 97 ABF Golf, idling keeps going to around 1300 RPM and sometimes around 1900 when driving. Hoping I can diagnose a bit with these, this is happening after replacing the ISV
