I just joined this forum so, hi everybody! I have a 2004 HCH with 5 speed tranny. I had the software updated about 6 months ago when I got the notification in the mail. I think it had something to do with better battery management or something. Well, I never had any problems with my car but might as well have it updated. Ever since, at random times, I'll come to a stop and the auto stop will not activate. Once this happens, it won't do the auto stop for the rest of the drive. If I "re-boot" the computer by turning the key all the way off and then restarting the car, I can drive it 50 feet, stop, and the auto stop works just fine. It will continue to work for a while but eventually I'll have to re-boot it again. I know there are certain requirements for the auto stop to function but all are being easily met. And, the fact that a simple restart makes everything work fine is another hint that it seems software related. Of course, it never does this on a test drive with a technician. So, for now, when it acts up, I just turn the car off myself and when the light turns green, I restart. But, I can do this with my Ford truck for crying out loud. Anybody else have this problem?

 

I can't help you with the problem, but welcome to the site!!

 

I have 60k on my '04 HCH MT, and have not noticed that problem. I have not had the software updated, however, as I loath the day I have to go to a dealer.

Normally, if I have autostop issues, I can usually find some reason for the lack of autostop. In the winter, running the fan when the outside ambient temperature is below (about) 35F will cancel autostop.

If you have been on the brakes hard and for a long period of time, the autostop will not engage until the vacuum boost is refreshed. Sometimes I will sit at a red light for a couple of seconds and *then* the autostop will engage.

You could have the defroster or air-conditioner on, or have disengaged the ECON option, both of which will cancel autostop.

Typically, when I am rolling toward a red light, I can engage the brake, move the transmission to neutral, and will see the car go into autostop at about 24 mph. I don't typically do this if the battery is below 1/2 full, then I let the regenetive braking kick in.

Sometimes, autostop won't engage when the battery is *very* low, one or two bars, but I have only seen this occur once, and can't confirm 100 percent that this is a hard rule or not.

Good Luck, Richard, and welcome to the site!

 

I notice that all of your observations are the same as mine when it comes to auto-stop. Your car acts just like mine in all of your scenarios. I have noticed that if there are one or two bars left, it won't auto-stop no matter what. I have even had such a dead IMA battery that the secondary starter was used to start the car. That was weird. So, dang...I shouldn't have updated my software. My rule of thumb is "if it ain't broke, don't fix it". But, I didn't listen to myself and screwed things up. It seems to act up about every 5 minutes of driving. Re-booting (re-starting) makes it happy for a while. I guess if the dealer doesn't want to or can't do anything about it, I'm going to sell it. Anybody interested? It has low miles as I drive it only one day a week.

 

Yeah...didn't think so....Prius is next on my list.