Intermittent not starting issue and the door locks, lock and unlock on their own?

SCOTT1216

MEMBER
2003 CHEVROLET MALIBU
3.1L
6 CYL
2WD
AUTOMATIC
150,000 MILES

My friend has the car listed above. Sometimes it won't start and has bad fuel pump symptoms (turning over faster than normal and not starting) While having the no start episodes, the door locks also lock and unlock on their own. After sitting for a while, it will start. She put it in the shop last week and they replaced the fuel pump, fuel pump relay and fuel filter. The car still has the problem. Any ideas?

Monday, August 26th, 2024 AT 11:47 AM

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
54,137 POSTS

The first thing that comes to mind is a weak battery, I would remove it and have it load tested at the auto parts store, if the battery is okay let's run the codes by doing a CAN scan which will go over the BCM which the door locks run through and can cause the engine not to start. Can I ask when the engine will not start is the security light flashing? You can get a CAN scanner (Controller Area Network) which will work on most cars from Amazon.

Here is a video to show you how:

https://youtu.be/u-4syLc-ifQ

Here is the body control module location which I would check the electrical connections for corrosion, and if there is none and you have codes for it, I would get a preprogrammed unit by searching Google or Ebay. Check out the images (below). Please let us know what happens.

Images (Click to make bigger)