PPV brake lights inop

[PPVconvert]

Thanks for having me on the forum. I bought a 2012 Tahoe SSV, with the 5.3, tow package (they never towed with it), locking rear, 2 speed xfer case, 85k miles.

Most everything is really good, except for the brake lights and reverse lights - they're inop. I used a OBD 2-way scanner and the BCM shows it's receiving the inputs and sending the signals to the lights but the lights don't get the message and I can't actuate the lights with teh scanner.

I believe that when they decommissioned the truck, they cut something and didn't reconnect. The lights, themselves look good and the ground for them does too. Where should I look to find the disconnected wires?

Great appreciation for your help.

 

[opfor2]

Dumb question but have you checked the fuses, are you getting power to the taillights are the bulb in working condition?

 

[PPVconvert]

Dumb question but have you checked the fuses, are you getting power to the taillights are the bulb in working condition?

Yes. I've checked all the fuses and they are good.

 

[mikez71]

Don't know if this will help, but some info on flasher units..

Instructions to a Whelen flasher unit..

Also here is an excerpt from the 2012 PPV brochure..

...

 

[opfor2]

View attachment 483562View attachment 483563

Yes. I've checked all the fuses and they are good.

How about the bulbs?

 

[JoeBlobs]

I would grab a multimeter or test light and start with checking for a signal at the BCM. For a 2014 (should be the same) reverse is a Dark Blue wire, white plug, pin 22. Brake wire is Light Blue/White wire, brown plug, pin 6.

You could look into the flasher situation like @mikez71 said as well. If you have RPO code 6J7 you'll have a flasher module from the factory which is located in the passenger side wheel well. Check out the upfitter guide for our trucks, lots of good info.

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please. If we can't see it, it does not exist.

You are already receiving sage advice from the knowledgeable folks on this Forum.

I believe that you can find the electrical wiring diagram on www.charm.li if you have to get into tracing wires.

 

[Pttsbrghfan]

I know on mine it has the surveillance mode setup, so the brake lights only operate when the truck is running.

 

[PPVconvert]

Don't know if this will help, but some info on flasher units..

Instructions to a Whelen flasher unit..
View attachment 483596
View attachment 483597
View attachment 483598

Also here is an excerpt from the 2012 PPV brochure..

View attachment 483595
...

Dude! Thank you. I will check all of this out on my Tahoe. This looks golden.

 

[Eighthtry]

How about wire harness connections. Those plugs may be different with a police package. It would be good to look at the wiring diagram for both to see if the inputs are the same. I bet that is your problem.