I could probably reach a wider audience in the General Forum, but just in case my problem is specific to the FEH/MMH somehow, I'll start here.

You know how the scangauge starts up the instant you unlock the car, but then if you don't turn the key to the "ON" position the displays on the SG cut off but the backlight stays on momentarily? I have an issue where sometimes if I unlock the car with the key fob to get something out of it, and then I shut and lock the door the backlight for the scangauge stays on until I get in the car and turn the key on. Has anyone else experienced this, and is there a fix?

 

That's been asked and answered before, and mine does that sometimes too. As I recall it had something to do with a transient condition on the data bus. You can probably search for the original thread.

Found it: https://www.greenhybrid.com/discuss/...ad.php?t=12233

 

Yes mine does that also.
It bugs me, but the power draw is so small, I've never had a hard time starting or anything after sitting there for 5 days, but I wouldn't want to leave it on longer that that.

 

I've had that happen in my TCH too. There seem to be a number of different scenarios. In the one, the ScanGaugeII (SG) wakes up when I unlock the car door, or some other activity occurs on the CAN bus while the car is "off," but it goes back to sleep shortly thereafter. In another case, the light stays on until the engine ECU is powered up; i.e., until the car is switched to ON or READY, and then it operates normally. A third case is similar to the second, but after powering up the car, SG returns to its default Home screen. What has happened is that SG has rebooted and done a "Connecting ..." operation behind the scenes without your knowledge, just as if it had been disconnected. [If you'd pressed the Home button while it was on, but before starting the car, you'd have seen the behind-the-scenes "Connecting ..." screen.] A fourth scenario, and by far the worst, is similar to the third, but now SG hangs up totally, will never reboot even if the car is started, the backlight stays on indefinitely, and it has to be unplugged to reset itself. You lose all your tank data. These are glitches that I have informed SG's Ron DeLong about, but I don't believe that he's yet figured out why it's happening.

It sounds as if your FEH is exhibiting some (all?) of these same problems.

Stan

 

To clarify the main menu goes away after about ten seconds of the doors being unlocked, but the backlight remains. I'm sure the activity on the CAN bus wakes it up and then when the SG realizes it's not needed it goes back to sleep, but forgets to shut off the backlight. It doesn't always happen- I'd say maybe one third of the time I unlock the vehicle without driving it I get this symptom. Luckily I've never had the fourth scenario that Stanley described.

John, I'm not worried about power draw, just the fact that when parked in the driveway, it's quite obvious to any hooligans cruising the street that there is a gadget in this car and it might be worth a smash and grab. If it were stolen I would be sad but I'd be more upset about a broken window. That's happened to me in previous cars and I've found that vacuuming out the little glass bits from all of the nooks and crannies of a car is about the worst job in the world!

 

I have had that concern too. Now, I just try to make sure I take everything out when I need it, so I won't need to enter the car later.

Also, just tonite, for the first time ever, my SG would not "Wake Up" even after the car was started and I was driving. The backlight was on, and the OBD cable was firmly attached. So at the first red stoplight, I cycled the key off, then back on, and it worked fine after that.

I don't know what's up with that, but we did have a 100 degree day today and the car was parked in sun. But when it didn't work, it was already night and only about 85 degrees, both inside the car, and out.
-John