That’s a good idea to check temps with the sensor plugged in, I need to try that sometime. Just don’t do what I did and leave it plugged in for over a week while your car sits in airport parking. Ran my battery down and for some reason all three jump attempts with various cables and jumper batteries failed. Had to take the battery to a auto parts store and get it checked then let it charge for a few hours to get back in business. Using an ammeter I was able to trace the draw to my OBDII sensor. So far the only time the car has stranded me and it is my one and only daily driver.

 

G'day John,

I had the same happen when I left my reader plugged in for over a week. I have since discovered that the reader has two power supplies, one switched and the other hot at all times.

Who knows why?

Cheers,
Jeff.

 

My cheapo ELM327 appears to only draw power from the unswitched supply, so I made it drink only switched power by putting in a modified extension with line 9 run to pin 16 and line 16 clipped.

This change appears to have made for some weirdness, though -- the available PID list is sometimes shortened to about a dozen if I don't connect my phone before starting the engine. I haven't driven enough to pin down that causal pattern completely yet though.

As for temps, on the few drives I've monitored it in wintry but above freezing weather, I'm generally seeing 80-86 up to 91°C. But on a downhill section of freeway, it dipped to 68 if I read it correctly, so it seems my thermostats are not closing very convincingly.