I have a 2011 chevy express 3500 LS that has a persistent cargo door open message on the dash and an alarm sound. The door is closed and I've even tried shorting pin 15 on the pink X6 connector on the body control module to ground like the schematic shows but no change. We also have an issue where the left turn signal fuse (Fuse 7 BCM 5) randomly blows and have not been able to find any shorts in the wiring. Could this point to a bad body control module?

I disconnected the speaker to at least stop the noise. "LOL"

Thanks

 

Do you have the rare left side cargo door (RPO E26)? If not, then pin 15 is nothing. You will want to use a volt meter to measure voltages on pins 12, 14, & 22.


Also, since it's called a "door open switch" , shorting it ground probably tells the BCM that the door is open.

Usually this is caused by a broken door wiring harness , where it bends back and forth.

 

Side doors on these vans just use contacts in the door opening, no wires.

 

It does not have a left rear side door. It is the rear double door that is the issue. The only switch that I found on the door is in the latch itself. It has 3 wires black/white, red/white and green. I checked the door wires and and the switch and they all test fine. The dome light also goes on and off as it should.
I will have to look at it more.

 

The rear doors do have a wire harness going into it, but it should have a long coiled section designed to eliminate the wear issue. You might have to continuity check the wires to the switch.

 

I found the issue with both the cargo door switch and the left turn signal. About 2 feet in from the door jam the wire bundle was rubbing on the seatbelt mount. It shorted both wires at the same time. All is well now.

Thanks for the help.

 

Glad you figured it out. Thanks for reporting back.