First Failure with '08 GXP

[BNaylor]

Well guys I experienced my first failure with my GXP today. 40450 miles. The crappy OE AC Delco battery went bad which was a Delco 85H7YR. For anyone else with a '05-'08 Pontiac Grand Prix GXP here are the symptoms.

After trying to start the engine obviously the starter would not engage. Then you get the horn sounding and several DIC error messages like stability system disabled, traction control disabled, battery saver mode active and charging system failure. The battery measured around 10.2 volts with a digital multimeter which is not good. It should be around 12.5 volts across the battery positive and negative terminals. I used a trickle charger to charge the battery for a few hours and took it out on a run to get it fully charged up but after turning the engine off back to the original symptoms.

So I shopped around for a new battery. After careful consideration went with another AC Delco battery from a local AC Delco parts store. The 85-6YR Professional which cost me $109 before taxes and no core charge. The GM list price is around $203. Ouch! This is the recommended replacement for the OE 85H7YR battery. Best part is it has a 72 month warranty and up to 30 months old the battery is replaced free of charge. Just save that receipt.

Removal of the old and installation of the new battery took about 90 minutes. Since there is no clearance to get the battery out you have to undo the main fuse and relay box assembly and then remove the bottom clam shell part to get the 4 electrical connectors off. After that you can get the fuse box out of the way to get the battery out. Installation went smoothly. Once the job is complete take it out for a long test drive to make sure the new battery is fully charged and monitor the battery voltage status at the uplevel DIC. Voltage range is 11.5 to 15.5 volts.

Hope this info helps someone else.

[BNaylor]

Some pics. The new AC Delco battery installed and shows not much room in that area to work but it can be done.

[olopezm]

Damn!

And I used to think getting the battery out of the '97 GP was a PITA, now I now I was wrong...

Good thing it was just the battery, hopefully it will help other users!

[tblake]

Bob, if you would stop running all those amplifiers and subs you wouldn't kill your battery!!!!

Only 590 CCA? No way that would crank over a V8 in MN when its -30 degree winchills. Man I wish I lived somewhere warm, although its starting to get nice again in MN.

No, but seriously, all manufacturers have issues with the batterys they put in new cars now days it seems like.

When did GM switch over to the top post vs the side post?

[richtazz]

Tim, GM started going back to top post batteries in 03-04, and most if not all were changed over as new models/body styles were introduced.

On the weather, we had a crazy one yesterday here in MI. I call it Apriling, as we had rain, sleet and snow all falling at the same time, with lightning and thunder to boot...it was bizarre!!!

[BNaylor]

Originally Posted by tblake

Bob, if you would stop running all those amplifiers and subs you wouldn't kill your battery!!!!

Just the stock Monsoon stereo system Tim. I've never had a OE AC Delco battery last beyond three years in any of my GM cars. Some were less as low as 1 year in my '79 Z28. Most of the time the failure occurs during the 3 yr/36K mile bumper to bumper part of the warranty so good to go there.

The other thing about this specific battery for the GXP are the dimensions. It is small. I checked with Sears for a Die Hard and they stated none were available for this model.

Hey Rich was the price good?

BTW - The battery for my Camaro SS is in the trunk.