Warning For Towing 2015-16 GMC Cars

[CA_Traveler]

On another board the battery very quickly runs down on a 2015 Acadia when following the GM directions for towing. The car is sold and documented as flat towable and a lot of effort was spent with the dealer and GM for a resolution.

The battery drain is VERY large and exceeds the capacity of any known toad charging system. The M&G toad brake installer said he could install 4 ga charging cables but wasn't sure that would solve the problem. A 4 ga cable is rather large in case you're not aware.

If a full battery disconnect was added it is estimated to take 4-5 minutes because of access to the battery location behind the rear seat and a bypass for the toad brake would be necessary.

From the latest post: "GM has stated that they are having problems with all levels of 2015 and 2016 GMC, Buick and Chevy regarding towing."

Just a heads up and this information may be inaccurate or incomplete.

[CA_Traveler]

Check your meter accuracy. Those voltages are unacceptable.

[BozemanTrail]

Interest bit of research I did overnight. Parked my 2015 Enclave in the garage as normal every night and I measured the battery and it was 12.2v. That was a little lower than I would have thought. So, now, this morning, I get up, before even putting the key in the ignition, it was 11.8v.

So, both of these seem lower than I'd think for a new car with a new battery. The 0.4v drop over night is interesting -- so, I'm wondering with the report above indicates that there are issues being just when towing.

[BozemanTrail]

CA Traveler wrote:
They have a 2015 Acadia. Update: After towing the battery was drained and shot after several months. GM has indicated that the drain cannot be fixed without causing problems elsewhere on the latest post.

The thread is Dead Tow Vehicle on Yahoo Group Monacoers.

Interesting, thanks. I have a 2015 Enclave that we'll be towing this summer. Likely I'll put a little cheap 12v battery voltmeter and keep an eye on it as I tow to see if the battery is getting drawn down each day. Sounds like they were cycling the battery each day as it was towed and the battery didn't like the deep cycling.

[CA_Traveler]

They have a 2015 Acadia. Update: After towing the battery was drained and shot after several months. GM has indicated that the drain cannot be fixed without causing problems elsewhere on the latest post.

The thread is Dead Tow Vehicle on Yahoo Group Monacoers.

[BozemanTrail]

CA Traveler wrote:
A fuse and the 50A was mentioned. They have been to the dealer multiple times and GM said they have a towing problem. Apparently they are following all of the instructions.

What other forum is the original thread?

[CA_Traveler]

A fuse and the 50A was mentioned. They have been to the dealer multiple times and GM said they have a towing problem. Apparently they are following all of the instructions.

[BozemanTrail]

Just double checking -- they are pulling the three fuses as detailed in the instructions?

6. To prevent the battery from draining while the vehicle is being towed, remove the 15 amp ECM fuse and the 15 amp OnStar fuse. These are in the battery compartment behind the passenger seat on the floor. Also, remove the 50 amp BATT1 fuse from the underhood fuse block and store all fuses in a safe location.