Think my CMax had a nervous breakdown

[mtb9153]

Was out driving home from a great Fathers Day picnic with my family and sister and her husband and kids.  Looked down at the left side screen and saw the picture I have attached.  This has to be a meltdown of some sort.  This mileage isn't possible from non energi model.  Especially my SEL which has been notorious for low mileage.  Thoughts???? 

Edited June 17, 2013 by mtb9153

[Jus-A-CMax]

mtb - should have showed us your Trip Summary / Trip 1 display, that would be more meaningful to help us diagnose - as we don't know what you did with the Avg MPG that you are showing. You could have reset it before the trip etc etc?

 

I got this from coming back from the golf course....

 

 

At least with the numbers I shown, we can probably conclude batts were used extensively, may be a squirt or 2 (which is close as I only had a little over 1/2 batts). Next time...

 

PS Before someone rides my a$$ about these numbers, I was on the way back from the gym and stopped at a course to do some practice - and this was on my last leg home, okay...and yeah, it was above 60+MPG for the trip :hi5:

Edited June 17, 2013 by Jus-A-CMax

[salsaguy]

it's possible if it was the instantaneous mpg screen which you can get super high mpg if coasting, but i guess it wasn't so.maybe a perfect trip for the cmax for all conditions, temp, batty, weight, accessories, downhill, etc....

[JulieB]

I've had 90+ MPG short trips. The car was mostly in EV mode.

[Laurel]

There is a regular short run to the grocery store that I do and coming home with warm car it is 2.6 L for 2.6 km. (90 US mpg).  Generally those short hops just kill our mileage going out before the car is warm and going to the store it will be 9.8 L.  We are routinely getting 4.0 L on long hops now, but the short hops we do are more frequent and that keeps our lifetime from improving beyond 5.3 L.

[SnowStorm]

You can certainly get 100+ mpg for a short trip (but not a whole tank!).  I coasted 5+ miles off a mountain (about 1000 foot drop) and managed to get this!

It actually went on up to 700+ but I didn't get a picture.  The ICE had only run for a few seconds at the top after I reset the trip 2.  I doubt your C-Max had a meltdown.

[SnitGTS]

I drove up to my friends house on Friday, there was a long but gentle down hill to get to his house and by the time I got there my battery was almost full.  I walked in and my friend needed to run to the bank, so I told him I'd drive since he hadn't seen my new car yet.  Drove 0.3 miles to the bank fully in EV mode and got 999.9 mpg, drove the 0.3 miles back and got the same 999.9 mpg.  

 

I've gotten that pulling into my garage before but never actually going any distance on a street.  Needless to say he was impressed!

[Jus-A-CMax]

You can certainly get 100+ mpg for a short trip (but not a whole tank!).  I coasted 5+ miles off a mountain (about 1000 foot drop) and managed to get this!

It actually went on up to 700+ but I didn't get a picture.  The ICE had only run for a few seconds at the top after I reset the trip 2.  I doubt your C-Max had a meltdown.

Hee...hee..that would be an AWESOME start to a 700 mile tank. Wish I had the upslope and a CMax elevator on the way back, lol.

[Noah Harbinger]

Yeah, context is always necessary. Was the number changing quickly, and did it drop down quickly the next time the ICE kiced in? Perhaps you reset the rolling-recent fuel economy by accident, or the computer forgot it, right at the start of a stretch of EV driving. 

Edited June 18, 2013 by Noah Harbinger

[Testdriver]

I've had a couple 100+ mpg trips on my 2.5 mile drive into my office. The net elevation drop is only 100 ft, so it's not a frequent occurrence, but it is possible.

[Noah Harbinger]

When I drive up the state I'll usually fill up the tank at the Flying J before dropping down into the central valley. Can't wait to see the trip MPG when I get to the bottom of that hill :)

[mtb9153]

I'm still concerned about my getting in the Max and starting it up only to get the ICE turning on immediately and the battery gauge shows a very low level when I know at my last shutoff the battery level was much higher at an acceptable level.  Something is bring my Battery levels down with sitting overnight.  I did a battery check a couple mornings back with my voltmeter.  Checking from the under hood at positive "red" terminal and the ground post, reading was 11.9 to 12.1, seemed to vary a bit, wasn't steady but could of been because of my connection.

[Noah Harbinger]

I'm still concerned about my getting in the Max and starting it up only to get the ICE turning on immediately and the battery gauge shows a very low level when I know at my last shutoff the battery level was much higher at an acceptable level.  Something is bring my Battery levels down with sitting overnight.  I did a battery check a couple mornings back with my voltmeter.  Checking from the under hood at positive "red" terminal and the ground post, reading was 11.9 to 12.1, seemed to vary a bit, wasn't steady but could of been because of my connection.

 

You're measuring the low-voltage battery, not the high-voltage battery. That would not affect whether the ICE runs. 

 

Before you measure it, make sure the doors are closed, all outside lights are off, all entertainment/IP screens and lights have shut off. 

 

Lots of people are getting low-voltage battery levels in that range, me included. But it doesn't affect whether the ICE turns on. 

 

From the manual (1st printing, p. 118): If you enabled the Coolant Temperature module in MyView, it will display:

 

 

• Blue thermometer : This indicates that the hybrid system is not warm enough to allow EV operation. The gasoline engine will run continuously when the indicator is blue. During silent key start mode, the thermometer indicator will be blue, but the gasoline engine will not run. This is the result of the vehicle computer allowing the engine to be cooler during the silent key start period. This is normal operation and does not indicate a problem with your vehicle. After the first engine start the indicator will turn white when the gasoline engine is warm enough to turn off. 

 

There's also this from the Unique Driving Characteristics > Frequently Asked Questions (1st printing, p. 182):

 

Why does it take a long time before the engine shuts down? 

 

There are several reasons the engine stays on for an extended amount of time when it is first started. One common reason is to ensure that the emissions components are warm enough to minimize tailpipe emissions. As the climate gets cooler, this engine-on time is extended. 

 

Basically what I've noticed is that when I start after the car's been sitting a while, it will stay in EV until it feels the need to recharge the battery or supplement battery power, at which point the ICE will start and stay on until the engine is warm, at which point it operates as expected. 

 

Of course, that wouldn't address why your battery is lower in the morning than when you left it. I would expect that you would see a higher level than you saw in the morning. (But you won't be able to probe it with your multimeter).

 

There is nothing on the high-voltage battery that should be draining when the car is not either in accessory mode or drive mode. It is supposed to be completely disconnected by a relay while the car is off - in fact, controlling that relay is the only truly mission-critical function of the 12v low-voltage battery. So if you're seeing that, that could be very bad - perhaps an internal short. If I were you, I would start by documenting it by taking pictures of the battery level immediately before shutoff and immediately after start. I don't think I would attempt to measure the voltage of the high-voltage battery directly. 

Edited June 19, 2013 by Noah Harbinger