Fail safe Engine Mode - 2009 GT500 (battery)

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dgc76 said:

Engine would crank, start, die and throw up fail safe engine mode. Seemed the starter was spinning the engine a little slow. Tested the battery and it was weak. Installed a new battery and it would spin the engine fine but would not start. Scanned it and the code was “control module failure“. Cleared the code and it started up immediately. Several forums and 2 techs said a bad battery woul not cause fail safe mode. Well, I guess it can. By the way, the old battery was 8 years old. I had kept it it on a battery minder desulfator maintainer.

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dgc76 said:

Engine would crank, start, die and throw up fail safe engine mode. Seemed the starter was spinning the engine a little slow. Tested the battery and it was weak. Installed a new battery and it would spin the engine fine but would not start. Scanned it and the code was “control module failure“. Cleared the code and it started up immediately. Several forums and 2 techs said a bad battery woul not cause fail safe mode. Well, I guess it can. By the way, the old battery was 8 years old. I had kept it it on a battery minder desulfator maintainer.

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I see you have been a member since 2014, but this is your 1st post, so welcome! Please add your car year under your screen name.

Just an idea... it's possible that your alternator died. I don't know what code you got but they are known to crap out after a while. I went through three of them before I got a Nations and was done with it.

And if it IS your alt, make sure you get the correct one for your year... I think the regulator is different on different years.