ZSkipper

4 Feb - Whahappened?? I fired up my 2018 C7 this morning, and drove a couple of miles to a parking lot. Everything perfect and normal! Went to a short meeting...came out, door opened, but with foot on brake, nothing happened! No lights, no starting, no nothing! Inserted my fob into the steering shaft slot...nothing. I installed a new battery last month, and everything has been functioning 100%...until this morning. Got a lift back home to retrieve the second fob, surmising the first one had developed a 'problem' since shutting the car down. Came back with the second fob (both batteries fresh within 2 months), and to my dismay,...nothing! No door unlock, no flashing lights...totally dead! So now what? Have any of you experienced this?

AZRenegade

Start with checking the battery connections and end with getting a tow to the dealership of your choice.

eboggs_jkvl

Ok, you tried on the FOB thing but you could have a dead battery in the FOB and still get the car to start by placing the FOB in the slot in the steering column. No start, would lead me back to your 12V battery.

Elmer

64drvr

What’s the voltage on the battery?

ZSkipper

Hi Elmer - Yes, both fobs have new batteries, and the car's battery is a month old. Very peculiar, and wonder if there's an MIU module or something that distributes the signal from the fob to the rest of the components...once it's solved, I'll post the solution...thx!!

ZSkipper

The voltage on the battery was 13.2 charging before I shut it off. Just don't know why it was totally dead, but will recheck all connections. Thx!

Factoid

Check your battery cables. It will take 2 minutes. My negative cable was loose once and caused this very problem.

ZSkipper

THANKS for all your concerns, recommendations and experiences. The C7 sat for 5hrs in the parking lot...totally dead when I left. I returned, tried the pax door, and surprisingly, it opened! I went around to the driver's side...it opened, and the dash lit up! Put my foot on the brake, hit the start button, and 'voila'! It fired right up! Drove a couple of miles back home, and all worked 'as advertised'! What in the world caused the original problem...I may never know!!??? Thanks again...! ~ Buzz

kodpkd

You really need to find out what caused it. You don't want this happening again away from home.

eboggs_jkvl

Check your cables at the battery. Make sure that they are aligned as they came from the factory AND tight. If you 12V is 1 month old, I'm assuming that you replaced the battery a month ago. Cables are very touchy at the battery and the first thing considered after a battery swap.

Elmer

ZSkipper

You're totally right! I don't want this to happen again...anywhere! So, I'll double-check all battery connections tomorrow, and see what's up...thanks again for all your recommendations!

ZSkipper

Just a follow-up to those who have been so kind to offer assistance with their responses; I just pulled back the carpet and foam cover to check all connections. The battery is a new AGM, exact fit, and the positive connections, negative connections and flimsy black wire are all 100% solidly connected. I just don't get it...what could have caused that total 'blackout', and then a resurrection all by itself? Wish I could get to the root of it...any further suggestions will be very greatly appreciated!!

C5FORFUN2

Aliens

Tinkertech

Control, alternate, delete...................

Reboot.

Remember, your driving a big computer.

H Watkins

ZSkipper

Yes, a huge computer! So, what's the process for 'control-alt-delete'...seriously?

eboggs_jkvl

Disconnect the NEG lead from the battery and give it a few miutes to make sure everything goes dead. Reconnect and index your windows and that will do it.

Elmer

ZSkipper

Thx, Elmer...heading to the garage as we speak to do as you recommend!!

Spaceme1117

I would recommend to check your ground connections for corrosion. This is a common problem on C5's and C6's.

Ex_F-Body_Enthusiast

Just curious, I see you're in NH; was there a radical ambient/outdoor temperature difference in those 5 hours? (cold to warm?)