Crank no start, codes U0140 and B1380

SAMMY151618

MEMBER
2007 CHEVROLET SUBURBAN
5.3L
V8
4WD
AUTOMATIC
270,000 MILES

I have the SUV listed above bought it had a bad BCM and PCM would start every once in awhile got the new BCM and PCM, but now nothing no crank, no start security light is on but won’t program the key codes it’s throwing are U0140 B1380 checked obvious grounds but I’m missing something. There is a module missing that’s below the driver door between the body and frame but I can’t figure out what the module is that’s missing it has 3 connectors that go to it. Please help!

3 Replies

JACOBANDNICKOLAS

MECHANIC
109,758 POSTS

Hi,

I believe what is missing is the EBCM (electronic brake control module). See pic 1 below and let me know if that is where you mean.

The U0140 indicates there is a loss of communication with the body control module and the B1380 indicates an issue between the body control module and the ignition switch.

To break it down further, the B1380 should be followed by two additional numbers. For example, B1380 01. The addition to the code indicates specific details.

Now, I suspect the problem is related to the body control module. Since there is no communication, that seems to be an issue. So, make sure the connections to the BCM are clean and tight. Also, keep in mind, the BCM itself (the new one) may be bad.

I attached the diagnostics below for the 1380 code. Take a look through them and let me know if you are comfortable doing them.

Here is a link you may find helpful:

https://www.2carpros.com/articles/how-to-check-wiring

Let me know what you find or if you have other questions.

Take care,

Joe

See pics below.

Images (Click to make bigger)