We drove it yesterday evening and it ran like normal. My wife went to leave for work and it was dead. She said it was making clicking noises. I had my brother switch the battery from another car that has a good battery. She said it won't make any noise when she tries to start it and that it displayed "Service Hybrid Engine" (She can't remember if it said Engine or just Service Hybrid). Her XM radio and all the lights worked though.

I seen on some other threads about a faulty tranny wiring harness with '08s. I'm at work so I can't look at it until this evening when I get home. But does anyone know where the chaffing occurs on the wires so I can take a look or where the harness is located? The basic warranty is up so I would like to do everything I can to fix it.

I will also look at the voltage to see what it says. This is our first problem with the truck.

 

Hi Daniel -

The issues with the auxiliary wiring harness usually are indicated by warning messages about "check stabilitrack" and "check brakes". The harness runs to the transmission and also connects with the Electronic Brake Control Module. The harness is visible if you look under the truck - it runs from an opening protected by a flap of plastic under the truck behind the drivers seat, along one of the frame rails and up under the dash. I believe the front connectors are behind the glove box? (you have to pull one of the front airbags to get to the front connectors). The current service bulletin says that if the harness is damaged it should be replaced rather then repaired (at least that is the message to dealers - ymmv)

The other diagnosis you've tried - the 12v battery - if that battery is low there isn't enough juice to power up all of the electronics and allow all of the computers to talk with each other. That can prevent the truck from starting. It sounds like you can get power to the electronics - at least enough to power up the DIC. You should cycle through that and see what the battery charge is listed as. If it drops too low (below 12v [or at or below 12v?]) - that may indicate the battery isn't supplying enough juice. The DIC only lists whole number voltages - so it's tough to tell if 12V is really 11.5V or 12.4V.

Just my uneducated guess from your description - the issue is somewhere besides the wiring harness or the 12v battery.

Also - I don't understand why the warranty on a 2009 would be up (unless 2009 warranty is much different from 2010 and 2011) - the basic coverage is 3 years/36k miles, the drivetrain warranty is 5 years/100k miles, hybrid components I believe are 8 years/150k miles. Sure sounds like a drivetrain or hybrid issue.

 

Lets say I get it towed (using dealers wrecker service) to the dealer and it's something there was a service bulletin on or it falls under warranty. Will they pay me back for the towing? I really don't feel like removing a whole bunch of stuff just to go fishing for something that may not be the problem.

And the 3/36k warranty I believe is for the powertrain (ICE).


I see you have a truck just like my wifes. Does your ICE come on real easy when you take off? When I drive the truck you have to take off so slow for it to stay using the batteries up to 29mph. It seems impossible to do and not take forever just to get to 20mph. She gets a combined 16.5mpg which is something we could've got in a regular truck without the extra expense of the Hybrid. To say I'm unimpressed with the truck is an under statement. I wish the Volt was available now to everyone.

 

Warranty information is here I believe it was the same warranty as in 2009. You could always press your blue OnStar button and ask them if you are still under warranty. I believe the blue button works even if you are not a subscriber as long as you haven't disabled OnStar.

Yes - to stay on pure battery you have to accelerate very slowly. Not something that is doable with traffic behind you. You really don't get the MPG savings from the pure EV mode - it is really mostly gained by the extra time in V4 mode vs. the non-hybrid.

With that said - my last tank I got 22 MPG and that included two trips from 6300 feet to 7700 feet to 0 feet and back. If I stay on the something flatter, in warmer weather, and off the highway I can milk 26-27 MPG out of it. Going from 6300 to 7700 to 0 on a 200 mile drive last week I managed 31 MPG.

Highway speeds on the flat - about 23 MPG. I'm still working on how to get that number up some.

The trick to getting better mileage seems to be to watch the Instantaneous MPG display on the DIC and try to keep the truck in 4 cylinder mode as much as possible. It will usually slip into V8 on inclines, but on flats you can pretty much keep it in V4. You sometimes have to back off the gas pedal for an instant to have it pop into V4. It's tougher to hold it in V4 when you drive 65+

I would question mileage rating of 21/22 or now in 2011 20/23 as I think that mileage is hard to get without paying a lot of attention to what you are doing. If I completely ignore the DIC and just drive - and still drive somewhat gently, I end up with 20 to 21 MPG. If I drive aggressively, I can easily drop it to 16-17 MPG, so I drive gently. As mentioned - if I work really hard under the proper roads and speed I can push it into the high 20's.

Hope that helps.

The Volt is an interesting car, but only goes 40 miles or less on pure battery power. In the cold weather that can dip close to 20 miles. Hills take even more miles out of it. It travels those miles on about $0.50 worth of electricity. However - after it runs out of electricity it is very inefficient getting only in the low 30's, and much worse on the hills.

The Volt is also not a 4wd car, doesn't haul a whole lot of fishing gear either, and doesn't tow the boat!

The Nissan LEAF is all electric and goes somewhere between 65 and 120 miles on a charge - with no gas backup.

The PHEV Prius will be out next year and early testers are getting 70-90 MPG out of it.

Pretty sure that truck is still under warranty - call your local dealer with your VIN number in hand and they can tell you, and tell you if you are still under towing warranty too.

 

I had 12v in the DIC and it would not start. the dealer will replace it under warranty.

 

The DIC showed 12 volts. I decided to have it towed to the dealer since the message from the DIC said, "Service Hybrid System".


And I'm more than likely going to trade it in on another hybrid car, Lexus 400h.

 

Daniel -

Any updates as to the source of the trouble?

 

Well they said they haven't dealt with hybrids before so they had to call the engineers and they gave them some steps to try. And nothing needed to be replaced. They ended up relearning the EBCM due to a code. I can write word for word if my wife has it if you want.


As for the mpg on the truck. I will say my wife is horrible at taking off and even driving down the highway. She takes off to fast and hates cruise control. I'm actually undecided on what to replace the truck with. We're looking at Sonata Hybrid, Chevy Volt or even just a regular vehicle with just an ICE but gets over 40mpg hwy (but can't be cheap looking).

 

Interesting. That EBCM is actually on the auxiliary wiring harness that has been the source of so much trouble.


Be aware that if you "leadfoot" even something as fuel efficient as a Prius, you can be down in the low 40's for MPG. It's not quite as bad as the truck because there is so much less mass in the Prius to get going, but you definitely can get "bad" mileage in the thing.

The same would be true of the Volt - fast starts and hard driving will significantly diminish the battery range. Just saying!

 

When I drive it I can get 18 mpg combined. I just can't keep the ICE from coming on when I take off after about 20ft. The truck is just to slow taking off with just the electric motor. It seems like if you engage the gas pedal more than 10% taking off the ICE has to kick on and help which completely ruins the whole point of it. My wife still loves the truck and after seeing a Volt she still prefers the truck. But I actually like the Volt a lot and will be getting one as soon as they can turn the tax credit into an instant rebate.