High Voltage Battery Failure (Update: False Alarm) - GreenHybrid

Everest · #1 (**permalink**) 10-31-2006, 08:03 AM

Well I took delivery of my 2007 Ford Escape Hybrid on Oct 14. Two weeks to the day after it was purchased it left me stranded in the middle of a busy street. After a tow the the dealership, and 6 hours of trouble shooting later they tell me that the main battery failed, and it will take some time to get a new one in. I guess they do not ship them via air... Ground only.

My question, has anybody else had this problem? Really destroys your confidence in the vehicle...

WaltPA · #2 (**permalink**) 10-31-2006, 08:41 AM

Gee, I wonder just how the entire battery pack fails? The D-size flashlight batteries are all partitioned out. While a couple could fail, I don't understand how that would cause the entire pack to down right completely fail.

Also, can the HV battery failure really cause the vehicle to become stranded? I mean, you can't even continue driving with just the ICE?

Everest · #3 (**permalink**) 10-31-2006, 08:58 AM

I can tell you what happened.. The vehicle would start,, I would put it into reverse, and the ICE would die. I would start getting errors on the display. It would say drivers door ajar, passenger door ajar, etc.... even service 4x4 soon, then it would say to come to a safe stop. At that point all would go dead... It would do this everytime....

GaryG · #4 (**permalink**) 10-31-2006, 09:13 AM

There are sealed conponents within the battery housing (same as the eCVT) that can fail and the only solution is replacement of the entire unit. A simple shorted or defective Fan in the housing would call for battery replacement.

Also, the HV battery is the only way to start the FEH, and Everest didn't indicate if he had any trouble lights or codes. If the MMH went EV when this ocurred, it was all over anyway. I would like to know if there were any trouble lights or messages on the dash.

GaryG

GaryG · #5 (**permalink**) 10-31-2006, 09:25 AM

Thanks Greg, I don't see any connection with the warnings and battery. My guess would have been the PCM.

GaryG

WaltPA · #6 (**permalink**) 10-31-2006, 10:00 AM

Quote:

Originally Posted by Everest

..., then it would say to come to a safe stop.

That message means that such a severe failure has occurred, that not even "limp home" mode is possible. The computer will attempt to keep the vehicle running just long enough for you to safely pull off the road and stop.

WaltPA · #7 (**permalink**) 10-31-2006, 10:02 AM

Quote:

Originally Posted by GaryG

There are sealed conponents within the battery housing (same as the eCVT) that can fail and the only solution is replacement of the entire unit. A simple shorted or defective Fan in the housing would call for battery replacement.

But would something like a defective fan cause a catastrophic, and total, failure?

wwest · #8 (**permalink**) 10-31-2006, 10:22 AM

Quote:

Originally Posted by Everest

I can tell you what happened.. The vehicle would start,, I would put it into reverse, and the ICE would die. I would start getting errors on the display. It would say drivers door ajar, passenger door ajar, etc.... even service 4x4 soon, then it would say to come to a safe stop. At that point all would go dead... It would do this everytime....

The ONLY source of reverse drive is the hybrid battery pack, there is no "reverse" in the gearbox.

Also the 12 volt accessory battery is kept charged by a DC-DC down converter.

So if the hybrid battery were to fail the 12 volt battery would soon follow, thus all of the diagnostic lights.

Shame you had to move it in reverse in order to drive to the dealer.

Puzzling that the ICE would start each time in that this requires that the hybrid battery be available to run "MG1" as a starter motor. But I could see that a low charge of the 12 volt battery as being the root cause of all of the above.

More likely therefore a DC-DC down converter failure.

wwest · #9 (**permalink**) 10-31-2006, 10:31 AM

Hmmmm...

"...the main battery failed,..."

Like you, I would assume, at least at first, that "the main battery" would mean the hybrid battery, now I'm not so certain. The only thing left that would lead me to think that "the main battery" means the hybrid battery is that I would think it would not take a week to get a replacement 12 volt accessory battery.

But then again....

Did the DC-DC downconverter fail and that resulted in the failure of the 12 volt accessory battery?

Is the 12 volt accessory battery somehow special or unique?

Or is it taking a week to get the down-converter AND a new 12 volt accessory battery "package"?

GaryG · #10 (**permalink**) 10-31-2006, 10:48 AM

The traction battery control module (TBCM) should have sent a message (DTC) to the PCM. If a fan or cooling system component was bad, the TBCM can stop charging and discharging with the PCM. Since Greg did not indicate seeing a Charging System Warning, but these other warnings:

"I can tell you what happened.. The vehicle would start,, I would put it into reverse, and the ICE would die. I would start getting errors on the display. It would say drivers door ajar, passenger door ajar, etc.... even service 4x4 soon, then it would say to come to a safe stop. At that point all would go dead... It would do this everytime...."

My thoughts are that the PCM had the error. The reason being that the PCM was receiving door ajar and service 4X4 soon and sending those messages as warnings.
I would be a little upset after they replaced the battery (two weeks) and then found out it was the PCM. After all, if the PCM indicated incorrect messages on the dash, the techs may have found incorrect TBCM DTC's. All guess work on my part.

GaryG