long time lurker, first time poster.
The temperature gauge on my information module is on zero - cold reading. This has been a slow degradation from flicking on and off rapidly... then slowly, now all together dead.
The symptoms I noticed before it died completely were:
When driving at speed it would drop out under load, eg when approaching an incline. This was very repeatable and predictable.
It would always come back when stopped at lights etc.
A loss of power, presumably some mild limp mode when the gauge was not reading.
Occasionally it would linger between the actual operating temp and zero, but would rise to operating temp just before cutting out.
It is noticeably effected by the ambient temperature - worse when it is cooler.
Since persistent no reading the symptoms are:
Fan running constantly, even at startup
Poorer performance than ever.
What I have done so far:
Replaced thermostat and coolant temp sensor - much more difficult on the T6 than my v70 was, this was months ago - no change at all.
Checked the wiring for wear/breakage, nothing evident, though it disappears into the harness very quickly.
Cleaned connectors and grounds
Ohm tested the new sensor - it is perfect, could even watch it change as the car cooled. Still zero reading.
Tested the input to the sensor from the ecu. Provided very solid 5 volts with key on.
Checked battery and charged it to 13.1 volts, this also reset the ECU.
Lots of wiggling.
Yet to test the driver information module, though to my understanding it is just a readout, no engine controls rely on its presence.
Does the software update that many s60's get apply here? Last time I had my transmission software checked it was $200 for them to tell me it was up to date. Wow.
Any help would be great, I really appreciate what you guys do here.
Thanks Josh.